blocks|key|1772325|text|JavaScript可以匹配正则表达式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1772326|emailAddress.match(+/+some_regex+/);|code-block|syntax|javascript|1772327|以下是电子邮件的RFC22正则表达式：|offset|length|1772328|%5E((?>[a-zA-Z\d!#$%25&'*%2B\-/=?%5E_`{%7C}~]%2B\x20*%7C"((?=[\x01-\x7f])[%5E"\\]%7C\\[\x01-\x7f])*
"\x20*)*(?<angle><))?((?!\.)(?>\.?[a-zA-Z\d!#$%25&'*%2B\-/=?%5E_`{%7C}~]%2B)%2B%7C"((?=[\x01-\x
7f])[%5E"\\]%7C\\[\x01-\x7f])*")@(((?!-)[a-zA-Z\d\-]%2B(?<!-)\.)%2B[a-zA-Z]{2,}%7C\[(((?(?<
!\[)\.)(25[0-5]%7C2[0-4]\d%7C[01]?\d?\d)){4}%7C[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])
[%5E\\\[\]]%7C\\[\x01-\x7f])%2B)\])(?(angle)>)$|1772329|entityMap|0|LINK|mutability|MUTABLE|url|https://www.rfc-editor.org/rfc/rfc22^0|0|0|8|5|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@$I|X|J|Y|1|Z]]|A|$]]|$1|K|3|L|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<p>JavaScript can match a regular expression:</p>
<pre><code>emailAddress.match( / some_regex /);
</code></pre>
<p>Here's an <a href="https://www.rfc-editor.org/rfc/rfc22" rel="noreferrer">RFC22</a> regular expression for emails:</p>
<pre><code>^((?&gt;[a-zA-Z\d!#$%&amp;'*+\-/=?^_`{|}~]+\x20*|&quot;((?=[\x01-\x7f])[^&quot;\\]|\\[\x01-\x7f])*
&quot;\x20*)*(?&lt;angle&gt;&lt;))?((?!\.)(?&gt;\.?[a-zA-Z\d!#$%&amp;'*+\-/=?^_`{|}~]+)+|&quot;((?=[\x01-\x
7f])[^&quot;\\]|\\[\x01-\x7f])*&quot;)@(((?!-)[a-zA-Z\d\-]+(?&lt;!-)\.)+[a-zA-Z]{2,}|\[(((?(?&lt;
!\[)\.)(25[0-5]|2[0-4]\d|[01]?\d?\d)){4}|[a-zA-Z\d\-]*[a-zA-Z\d]:((?=[\x01-\x7f])
[^\\\[\]]|\\[\x01-\x7f])+)\])(?(angle)&gt;)$
</code></pre>


blocks|key|1557196|text|使用regular+expressions可能是最好的方法。你可以看到一系列的测试here+(取自chromium)|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1557197|const+validateEmail+=+(email)+=>+{
++return+String(email)
++++.toLowerCase()
++++.match(
++++++/%5E(([%5E<>()[\]\\.,;:\s@"]%2B(\.[%5E<>()[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/
++++);
};|code-block|syntax|javascript|1557198|以下是接受unicode的常规表达式的示例：|1557199|const+re+=
++/%5E(([%5E<>()[\]\.,;:\s@\"]%2B(\.[%5E<>()[\]\.,;:\s@\"]%2B)*)%7C(\".%2B\"))@(([%5E<>()[\]\.,;:\s@\"]%2B\.)%2B[%5E<>()[\]\.,;:\s@\"]{2,})$/i;|1557200|但请记住，不应该只依赖JavaScript验证。可以很容易地禁用JavaScript。这也应该在服务器端进行验证。|1557201|以下是上述操作的一个示例：|1557202|const+validateEmail+=+(email)+=>
++return+email.match(
++++/%5E(([%5E<>()[\]\\.,;:\s@\"]%2B(\.[%5E<>()[\]\\.,;:\s@\"]%2B)*)%7C(\".%2B\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/
++);
};

const+validate+=+()+=>+{
++const+$result+=+$('#result');
++const+email+=+$('#email').val();
++$result.text('');

++if+(validateEmail(email))+{
++++$result.text(email+%2B+'+is+valid+:)');
++++$result.css('color',+'green');
++}+else+{
++++$result.text(email+%2B+'+is+not+valid+:(');
++++$result.css('color',+'red');
++}
++return+false;
}

$('#email').on('input',+validate);|1557203|这是html|style|CODE|1557204|<script+src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<label+for="email">Enter+an+email+address:+</label>
<input+id="email"+/>
<h2+id="result"></h2>|1557205|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Regular_expression|1|http://jsfiddle.net/ghvj4gy9/embedded/result,js/|2|https://cs.chromium.org/chromium/src/third_party/blink/web_tests/fast/forms/resources/ValidityState-typeMismatch-email.js?q=ValidityState-typeMismatch-email.js&sq=package:chromium&dr^0|2|J|0|15|4|1|1D|8|2|0|0|0|0|0|0|0|2|4|0|0^^$0|@$1|2|3|4|5|6|7|1A|8|@]|9|@$A|1B|B|1C|1|1D]|$A|1E|B|1F|1|1G]|$A|1H|B|1I|1|1J]]|C|$]]|$1|D|3|E|5|F|7|1K|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|1L|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|1M|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|1N|8|@]|9|@]|C|$]]|$1|O|3|P|5|6|7|1O|8|@]|9|@]|C|$]]|$1|Q|3|R|5|F|7|1P|8|@]|9|@]|C|$G|H]]|$1|S|3|T|5|6|7|1Q|8|@$A|1R|B|1S|U|V]]|9|@]|C|$]]|$1|W|3|X|5|F|7|1T|8|@]|9|@]|C|$G|H]]|$1|Y|3|-4|5|6|7|1U|8|@]|9|@]|C|$]]]|Z|$10|$5|11|12|13|C|$14|15]]|16|$5|11|12|13|C|$14|17]]|18|$5|11|12|13|C|$14|19]]]]

<p>Using <a href="http://en.wikipedia.org/wiki/Regular_expression" rel="noreferrer">regular expressions</a> is probably the best way. You can see a bunch of tests <a href="http://jsfiddle.net/ghvj4gy9/embedded/result,js/" rel="noreferrer">here</a> (taken from <a href="https://cs.chromium.org/chromium/src/third_party/blink/web_tests/fast/forms/resources/ValidityState-typeMismatch-email.js?q=ValidityState-typeMismatch-email.js&amp;sq=package:chromium&amp;dr" rel="noreferrer">chromium</a>)</p>
<pre class="lang-js prettyprint-override"><code>const validateEmail = (email) =&gt; {
  return String(email)
    .toLowerCase()
    .match(
      /^(([^&lt;&gt;()[\]\\.,;:\s@&quot;]+(\.[^&lt;&gt;()[\]\\.,;:\s@&quot;]+)*)|(&quot;.+&quot;))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
    );
};
</code></pre>
<p>Here's the example of regular expresion that accepts unicode:</p>
<pre class="lang-js prettyprint-override"><code>const re =
  /^(([^&lt;&gt;()[\]\.,;:\s@\&quot;]+(\.[^&lt;&gt;()[\]\.,;:\s@\&quot;]+)*)|(\&quot;.+\&quot;))@(([^&lt;&gt;()[\]\.,;:\s@\&quot;]+\.)+[^&lt;&gt;()[\]\.,;:\s@\&quot;]{2,})$/i;
</code></pre>
<p>But keep in mind that one should not rely only upon JavaScript validation. JavaScript can easily be disabled. This should be validated on the server side as well.</p>
<p>Here's an example of the above in action:</p>
<pre class="lang-js prettyprint-override"><code>const validateEmail = (email) =&gt;
  return email.match(
    /^(([^&lt;&gt;()[\]\\.,;:\s@\&quot;]+(\.[^&lt;&gt;()[\]\\.,;:\s@\&quot;]+)*)|(\&quot;.+\&quot;))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
  );
};

const validate = () =&gt; {
  const $result = $('#result');
  const email = $('#email').val();
  $result.text('');

  if (validateEmail(email)) {
    $result.text(email + ' is valid :)');
    $result.css('color', 'green');
  } else {
    $result.text(email + ' is not valid :(');
    $result.css('color', 'red');
  }
  return false;
}

$('#email').on('input', validate);
</code></pre>
<p>And this is the <code>html</code>:</p>
<pre class="lang-html prettyprint-override"><code>&lt;script src=&quot;https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js&quot;&gt;&lt;/script&gt;

&lt;label for=&quot;email&quot;&gt;Enter an email address: &lt;/label&gt;
&lt;input id=&quot;email&quot; /&gt;
&lt;h2 id=&quot;result&quot;&gt;&lt;/h2&gt;
</code></pre>


blocks|key|1557325|text|哇，这里有很多复杂的东西。如果你想要做的只是捕捉最明显的语法错误，我会这样做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1557326|%5E\S%2B@\S%2B$|code-block|syntax|javascript|1557327|它通常会捕获用户犯下的最明显的错误，并确保表单大部分是正确的，这就是JavaScript验证的意义所在。|1557328|编辑:我们还可以检查“.”在电子邮件中使用|1557329|/%5E\S%2B@\S%2B\.\S%2B$/|1557330|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

<p>Wow, there are lots of complexity here. If all you want to do is just catch the most obvious syntax errors, I would do something like this:</p>
<pre><code>^\S+@\S+$
</code></pre>
<p>It usually catches the most obvious errors that the user makes and assures that the form is mostly right, which is what JavaScript validation is all about.</p>
<p>EDIT:
We can also check for '.' in the email using</p>
<pre><code>/^\S+@\S+\.\S+$/
</code></pre>


blocks|key|1772618|text|当你决定使用正则表达式来验证电子邮件时，有一件事你必须要理解：It's+probably+not+a+good+idea。一旦你接受了这一点，有很多实现可以让你走到一半，this+article+sums+them+up+nicely.|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1772619|然而，简而言之，要绝对、肯定地确定用户输入的内容实际上是一封电子邮件，唯一的方法就是实际发送一封电子邮件，看看会发生什么。除此之外，这一切都只是猜测。|1772620|entityMap|0|LINK|mutability|MUTABLE|url|http://ex-parrot.com/~pdw/Mail-RFC822-Address.html|1|http://www.regular-expressions.info/email.html^0|V|T|0|2D|X|1|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]|$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|-4|5|6|7|X|8|@]|9|@]|C|$]]]|G|$H|$5|I|J|K|C|$L|M]]|N|$5|I|J|K|C|$L|O]]]]

<p>There's something you have to understand the second you decide to use a regular expression to validate emails: <a href="http://ex-parrot.com/~pdw/Mail-RFC822-Address.html" rel="noreferrer">It's probably not a good idea</a>. Once you have come to terms with that, there are many implementations out there that can get you halfway there, <a href="http://www.regular-expressions.info/email.html" rel="noreferrer">this article sums them up nicely.</a></p>

<p>In short, however, the only way to be absolutely, positively sure that what the user entered is in fact an email is to actually send an email and see what happens. Other than that it's all just guesses.</p>


blocks|key|1557431|text|这是从http://codesnippets.joyent.com/posts/show/1917偷来的|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1557432|email+=+$('email');
filter+=+/%5E([a-zA-Z0-9_\.\-])%2B\@(([a-zA-Z0-9\-])%2B\.)%2B([a-zA-Z0-9]{2,4})%2B$/;
if+(filter.test(email.value))+{
++//+Yay!+valid
++return+true;
}
else
++{return+false;}|code-block|syntax|javascript|1557433|entityMap|0|LINK|mutability|MUTABLE|url|http://codesnippets.joyent.com/posts/show/1917^0|3|1A|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

<p>This was stolen from <a href="http://codesnippets.joyent.com/posts/show/1917" rel="noreferrer">http://codesnippets.joyent.com/posts/show/1917</a></p>

<pre><code>email = $('email');
filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
if (filter.test(email.value)) {
  // Yay! valid
  return true;
}
else
  {return false;}
</code></pre>


blocks|key|1772680|text|下面是正则表达式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1772681|/%5E([\w]%2B)(.[\w]%2B)*@([\w]%2B)(.[\w]{2,3}){1,2}$/;|code-block|syntax|javascript|1772682|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Following regular expression:</p>

<pre><code>/^([\w]+)(.[\w]+)*@([\w]+)(.[\w]{2,3}){1,2}$/;
</code></pre>


blocks|key|1772724|text|让电子邮件验证器100%25正确是很难的。唯一真正正确的方法是向帐户发送一封测试电子邮件。也就是说，有一些基本的检查可以帮助确保你得到的东西是合理的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1772725|一些需要改进的地方：|1772726|不需要新的RegExp，只需像这样编写regexp就可以了：|offset|length|style|CODE|1772727|if+(reg.test(/@/))|code-block|syntax|javascript|1772728|其次，检查以确保句点在@符号之后，并确保在@和句点之间有字符。|1772729|entityMap^0|0|0|5|6|J|6|0|0|B|1|L|1|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|U|8|@$F|V|G|W|H|I]|$F|X|G|Y|H|I]]|9|@]|A|$]]|$1|J|3|K|5|L|7|Z|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|10|8|@$F|11|G|12|H|I]|$F|13|G|14|H|I]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|R|$]]

<p>It's hard to get an email validator 100% correct. The only real way to get it correct would be to send a test email to the account. That said, there are a few basic checks that can help make sure that you're getting something reasonable.</p>

<p>Some things to improve:</p>

<p>Instead of new <code>RegExp</code>, just try writing the <code>regexp</code> out like this:</p>

<pre><code>if (reg.test(/@/))
</code></pre>

<p>Second, check to make sure that a period comes after the <code>@</code> sign, and make sure that there are characters between the <code>@</code>s and periods. </p>


blocks|key|1557538|text|下面是关于使用正则表达式验证电子邮件地址的一个很好的讨论；"Comparing+E-mail+Address+Validating+Regular+Expressions“|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1557539|下面是当前的top表达式，即与JavaScript兼容的表达式，以供参考：|1557540|/%5E[-a-z0-9~!$%25%5E&*_=%2B}{\'?]%2B(\.[-a-z0-9~!$%25%5E&*_=%2B}{\'?]%2B)*@([a-z0-9_][-a-z0-9_]*(\.[-a-z0-9_]%2B)*\.(aero%7Carpa%7Cbiz%7Ccom%7Ccoop%7Cedu%7Cgov%7Cinfo%7Cint%7Cmil%7Cmuseum%7Cname%7Cnet%7Corg%7Cpro%7Ctravel%7Cmobi%7C[a-z][a-z])%7C([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,5})?$/i|code-block|syntax|javascript|1557541|entityMap|0|LINK|mutability|MUTABLE|url|http://fightingforalostcause.net/misc/2006/compare-email-regex.php^0|U|1J|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

<p>Here is a very good discussion about using regular expressions to validate email addresses; "<a href="http://fightingforalostcause.net/misc/2006/compare-email-regex.php" rel="noreferrer">Comparing E-mail Address Validating Regular Expressions</a>"</p>

<p>Here is the current top expression, that is JavaScript compatible, for reference purposes:</p>

<pre><code>/^[-a-z0-9~!$%^&amp;*_=+}{\'?]+(\.[-a-z0-9~!$%^&amp;*_=+}{\'?]+)*@([a-z0-9_][-a-z0-9_]*(\.[-a-z0-9_]+)*\.(aero|arpa|biz|com|coop|edu|gov|info|int|mil|museum|name|net|org|pro|travel|mobi|[a-z][a-z])|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,5})?$/i
</code></pre>


blocks|key|1557586|text|显然，就是这样：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1557587|/%5E([\w\!\#$\%25\&\'\*\%2B\-\/\=\?\%5E\`{\%7C\}\~]%2B\.)*[\w\!\#$\%25\&\'\*\%2B\-\/\=\?\%5E\`{\%7C\}\~]%2B@((((([a-z0-9]{1}[a-z0-9\-]{0,62}[a-z0-9]{1})%7C[a-z])\.)%2B[a-z]{2,6})%7C(\d{1,3}\.){3}\d{1,3}(\:\d{1,5})?)$/i|code-block|syntax|javascript|1557588|取自http://fightingforalostcause.net/misc/2006/compare-email-regex.php，10月1日‘10日。|offset|length|1557589|但是，当然，这是对国际化的忽视。|1557590|entityMap|0|LINK|mutability|MUTABLE|url|http://fightingforalostcause.net/misc/2006/compare-email-regex.php^0|0|0|2|1U|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@$I|X|J|Y|1|Z]]|A|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<p>Apparently, that's it:</p>

<pre><code>/^([\w\!\#$\%\&amp;\'\*\+\-\/\=\?\^\`{\|\}\~]+\.)*[\w\!\#$\%\&amp;\'\*\+\-\/\=\?\^\`{\|\}\~]+@((((([a-z0-9]{1}[a-z0-9\-]{0,62}[a-z0-9]{1})|[a-z])\.)+[a-z]{2,6})|(\d{1,3}\.){3}\d{1,3}(\:\d{1,5})?)$/i
</code></pre>

<p>Taken from <a href="http://fightingforalostcause.net/misc/2006/compare-email-regex.php" rel="noreferrer">http://fightingforalostcause.net/misc/2006/compare-email-regex.php</a> on Oct 1 '10.</p>

<p>But, of course, that's ignoring internationalization.</p>


blocks|key|1772878|text|您不应该使用正则表达式来验证输入字符串，以检查它是否是电子邮件。它太复杂了，不可能涵盖所有的情况。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1772879|现在，由于您只能涵盖90%25的情况，因此可以编写如下内容：|1772880|function+isPossiblyValidEmail(txt)+{
+++return+txt.length+>+5+&&+txt.indexOf('@')>0;
}|code-block|syntax|javascript|1772881|您可以对其进行改进。例如，'aaa@‘是有效的。但总体而言，你得到了要点。别得意忘形...一个简单的90%25的解决方案比100%25的解决方案更好。|1772882|世界需要更简单的代码..。|1772883|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

<p>You should not use regular expressions to validate an input string to check if it's an email. It's too complicated and would not cover all the cases.</p>

<p>Now since you can only cover 90% of the cases, write something like:</p>

<pre><code>function isPossiblyValidEmail(txt) {
   return txt.length &gt; 5 &amp;&amp; txt.indexOf('@')&gt;0;
}
</code></pre>

<p>You can refine it. For instance, 'aaa@' is valid. But overall you get the gist. And don't get carried away... A simple 90% solution is better than 100% solution that does not work. </p>

<p>The world needs simpler code...</p>


blocks|key|1557727|text|我稍微修改了一下Jaymon's+answer，以满足那些希望以以下形式进行简单验证的人：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1557728|anystring@anystring.anystring|code-block|syntax|javascript|1557729|正则表达式：|1557730|/\S%2B@\S%2B\.\S%2B/|1557731|要防止匹配多个@符号，请执行以下操作：|1557732|/%5E[%5E\s@]%2B@[%5E\s@]%2B\.[%5E\s@]%2B$/|1557733|JavaScript函数示例：|1557734|​|1557735|function+validateEmail(email)+
++++{
++++++++var+re+=+/\S%2B@\S%2B\.\S%2B/;
++++++++return+re.test(email);
++++}
++++
console.log(validateEmail('anystring@anystring.anystring'));|1557736|1557737|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/48800/4832311^0|8|F|0|0|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|15|8|@]|9|@$A|16|B|17|1|18]]|C|$]]|$1|D|3|E|5|F|7|19|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|1A|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|1B|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|1C|8|@]|9|@]|C|$]]|$1|O|3|P|5|F|7|1D|8|@]|9|@]|C|$G|H]]|$1|Q|3|R|5|6|7|1E|8|@]|9|@]|C|$]]|$1|S|3|T|5|6|7|1F|8|@]|9|@]|C|$]]|$1|U|3|V|5|F|7|1G|8|@]|9|@]|C|$G|H]]|$1|W|3|T|5|6|7|1H|8|@]|9|@]|C|$]]|$1|X|3|-4|5|6|7|1I|8|@]|9|@]|C|$]]]|Y|$Z|$5|10|11|12|C|$13|14]]]]

<p>I've slightly modified <a href="https://stackoverflow.com/a/48800/4832311">Jaymon's answer</a> for people who want really simple validation in the form of:</p>
<pre><code>anystring@anystring.anystring
</code></pre>
<p>The regular expression:</p>
<pre><code>/\S+@\S+\.\S+/
</code></pre>
<p>To prevent matching multiple @ signs:</p>
<pre><code>/^[^\s@]+@[^\s@]+\.[^\s@]+$/
</code></pre>
<p>Example JavaScript function:</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function validateEmail(email) 
    {
        var re = /\S+@\S+\.\S+/;
        return re.test(email);
    }
    
console.log(validateEmail('anystring@anystring.anystring'));</code></pre>
</div>
</div>
</p>


blocks|key|1557783|text|Sectrean的解决方案工作得很好，但它没有通过我的linter。所以我添加了一些转义：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1557784|function+validateEmail(email){+
+++++var+re+=+/%5E(([%5E<>()[]\\.,;:\s@\"]%2B(\.[%5E<>()[]\\.,;:\s@\"]%2B)*)%7C(\".%2B\"))@(([[0-9]{1,3}\‌​.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/;+
+++++return+re.test(email);+
}|code-block|syntax|javascript|1557785|entityMap|0|LINK|mutability|MUTABLE|url|https://en.wikipedia.org/wiki/Lint_%2528software%2529^0|R|6|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

<p>Sectrean's solution works great, but it was failing my <a href="https://en.wikipedia.org/wiki/Lint_%28software%29" rel="nofollow">linter</a>. So I added some escapes:</p>

<pre><code>function validateEmail(email){ 
     var re = /^(([^&lt;&gt;()[]\\.,;:\s@\"]+(\.[^&lt;&gt;()[]\\.,;:\s@\"]+)*)|(\".+\"))@(([[0-9]{1,3}\‌​.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/; 
     return re.test(email); 
}
</code></pre>


blocks|key|1773010|text|function+validateEmail(elementValue){++++++++
++++var+emailPattern+=+/%5E[a-zA-Z0-9._]%2B[a-zA-Z0-9]%2B@[a-zA-Z0-9]%2B\.[a-zA-Z]{2,4}$/;++
++++return+emailPattern.test(elementValue);+++
++}+++|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1773011|如果电子邮件地址有效，则返回true。否则，它将返回false。|unstyled|1773012|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>function validateEmail(elementValue){        
    var emailPattern = /^[a-zA-Z0-9._]+[a-zA-Z0-9]+@[a-zA-Z0-9]+\.[a-zA-Z]{2,4}$/;  
    return emailPattern.test(elementValue);   
  }   
</code></pre>

<p>It returns true if the email address is valid. Otherwise, it will return false.</p>


blocks|key|1773060|text|在现代浏览器中，您可以使用纯JavaScript和DOM在@Sushil回答的基础上进行构建|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1773061|function+validateEmail(value)+{
++var+input+=+document.createElement('input');

++input.type+=+'email';
++input.required+=+true;
++input.value+=+value;

++return+typeof+input.checkValidity+===+'function'+?+input.checkValidity()+:+/\S%2B@\S%2B\.\S%2B/.test(value);
}|code-block|syntax|javascript|1773062|我在fiddle+http://jsfiddle.net/boldewyn/2b6d5/中做了一个例子。与特征检测和Squirtle's+Answer的基本验证相结合，它将您从正则表达式大屠杀中解脱出来，并且不会在旧浏览器上出现问题。|1773063|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Document_Object_Model|1|http://jsfiddle.net/boldewyn/2b6d5/|2|https://stackoverflow.com/a/9204568/324094^0|P|3|0|0|0|9|Z|1|1M|H|2|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@$A|12|B|13|1|14]|$A|15|B|16|1|17]]|C|$]]|$1|K|3|-4|5|6|7|18|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]|S|$5|N|O|P|C|$Q|T]]|U|$5|N|O|P|C|$Q|V]]]]

<p>In modern browsers you can build on top of @Sushil's answer with pure JavaScript and the <a href="http://en.wikipedia.org/wiki/Document_Object_Model" rel="noreferrer">DOM</a>:</p>

<pre><code>function validateEmail(value) {
  var input = document.createElement('input');

  input.type = 'email';
  input.required = true;
  input.value = value;

  return typeof input.checkValidity === 'function' ? input.checkValidity() : /\S+@\S+\.\S+/.test(value);
}
</code></pre>

<p>I've put together an example in the fiddle <a href="http://jsfiddle.net/boldewyn/2b6d5/" rel="noreferrer">http://jsfiddle.net/boldewyn/2b6d5/</a>. Combined with feature detection and the bare-bones validation from <a href="https://stackoverflow.com/a/9204568/324094">Squirtle's Answer</a>, it frees you from the regular expression massacre and does not bork on old browsers.</p>


blocks|key|1557910|text|​|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1557911|var+testresults

function+checkemail()+{
++var+str+=+document.validation.emailcheck.value
++var+filter+=+/%5E([\w-]%2B(?:\.[\w-]%2B)*)@((?:[\w-]%2B\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
++if+(filter.test(str))
++++testresults+=+true
++else+{
++++alert("Please+input+a+valid+email+address!")
++++testresults+=+false
++}
++return+(testresults)
}

function+checkbae()+{
++if+(document.layers+%7C%7C+document.getElementById+%7C%7C+document.all)
++++return+checkemail()
++else
++++return+true
}|code-block|syntax|javascript|1557912|<form+name="validation"+onSubmit="return+checkbae()">
++Please+input+a+valid+email+address:<br+/>

++<input+type="text"+size=18+name="emailcheck">
++<input+type="submit"+value="Submit">
</form>|1557913|1557914|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|M|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|I|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|K|$]]

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>var testresults

function checkemail() {
  var str = document.validation.emailcheck.value
  var filter = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
  if (filter.test(str))
    testresults = true
  else {
    alert("Please input a valid email address!")
    testresults = false
  }
  return (testresults)
}

function checkbae() {
  if (document.layers || document.getElementById || document.all)
    return checkemail()
  else
    return true
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;form name="validation" onSubmit="return checkbae()"&gt;
  Please input a valid email address:&lt;br /&gt;

  &lt;input type="text" size=18 name="emailcheck"&gt;
  &lt;input type="submit" value="Submit"&gt;
&lt;/form&gt;</code></pre>
</div>
</div>
</p>


blocks|key|1773136|text|我对regular+expressions的了解不是很好。这就是为什么我先用一个简单的正则表达式检查一般语法，然后再用其他函数检查更具体的选项。这可能不是最好的技术解决方案，但这样我会更灵活和更快。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1773137|我遇到的最常见的错误是空格(尤其是在开头和结尾)，偶尔还会出现双点。|1773138|function+check_email(val){
++++if(!val.match(/\S%2B@\S%2B\.\S%2B/)){+//+Jaymon's+/+Squirtle's+solution
++++++++//+Do+something
++++++++return+false;
++++}
++++if(+val.indexOf('+')!=-1+%7C%7C+val.indexOf('..')!=-1){
++++++++//+Do+something
++++++++return+false;
++++}
++++return+true;
}

check_email('check@thiscom');+//+Returns+false
check_email('check@this..com');+//+Returns+false
check_email('+check@this.com');+//+Returns+false
check_email('check@this.com');+//+Returns+true|code-block|syntax|javascript|1773139|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Regular_expression^0|2|J|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

<p>My knowledge of <a href="http://en.wikipedia.org/wiki/Regular_expression" rel="noreferrer">regular expressions</a> is not that good. That's why I check the general syntax with a simple regular expression first and check more specific options with other functions afterwards. This may not be not the best technical solution, but this way I'm way more flexible and faster.</p>

<p>The most common errors I've come across are spaces (especially at the beginning and end) and occasionally a double dot.</p>

<pre><code>function check_email(val){
    if(!val.match(/\S+@\S+\.\S+/)){ // Jaymon's / Squirtle's solution
        // Do something
        return false;
    }
    if( val.indexOf(' ')!=-1 || val.indexOf('..')!=-1){
        // Do something
        return false;
    }
    return true;
}

check_email('check@thiscom'); // Returns false
check_email('check@this..com'); // Returns false
check_email(' check@this.com'); // Returns false
check_email('check@this.com'); // Returns true
</code></pre>


blocks|key|1558005|text|这是正确的RFC822版本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1558006|function+checkEmail(emailAddress)+{
++var+sQtext+=+'[%5E\\x0d\\x22\\x5c\\x80-\\xff]';
++var+sDtext+=+'[%5E\\x0d\\x5b-\\x5d\\x80-\\xff]';
++var+sAtom+=+'[%5E\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]%2B';
++var+sQuotedPair+=+'\\x5c[\\x00-\\x7f]';
++var+sDomainLiteral+=+'\\x5b('+%2B+sDtext+%2B+'%7C'+%2B+sQuotedPair+%2B+')*\\x5d';
++var+sQuotedString+=+'\\x22('+%2B+sQtext+%2B+'%7C'+%2B+sQuotedPair+%2B+')*\\x22';
++var+sDomain_ref+=+sAtom;
++var+sSubDomain+=+'('+%2B+sDomain_ref+%2B+'%7C'+%2B+sDomainLiteral+%2B+')';
++var+sWord+=+'('+%2B+sAtom+%2B+'%7C'+%2B+sQuotedString+%2B+')';
++var+sDomain+=+sSubDomain+%2B+'(\\x2e'+%2B+sSubDomain+%2B+')*';
++var+sLocalPart+=+sWord+%2B+'(\\x2e'+%2B+sWord+%2B+')*';
++var+sAddrSpec+=+sLocalPart+%2B+'\\x40'+%2B+sDomain;+//+complete+RFC822+email+address+spec
++var+sValidEmail+=+'%5E'+%2B+sAddrSpec+%2B+'$';+//+as+whole+string

++var+reValidEmail+=+new+RegExp(sValidEmail);

++return+reValidEmail.test(emailAddress);
}|code-block|syntax|javascript|1558007|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>This is the correct RFC822 version.</p>

<pre><code>function checkEmail(emailAddress) {
  var sQtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
  var sDtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
  var sAtom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
  var sQuotedPair = '\\x5c[\\x00-\\x7f]';
  var sDomainLiteral = '\\x5b(' + sDtext + '|' + sQuotedPair + ')*\\x5d';
  var sQuotedString = '\\x22(' + sQtext + '|' + sQuotedPair + ')*\\x22';
  var sDomain_ref = sAtom;
  var sSubDomain = '(' + sDomain_ref + '|' + sDomainLiteral + ')';
  var sWord = '(' + sAtom + '|' + sQuotedString + ')';
  var sDomain = sSubDomain + '(\\x2e' + sSubDomain + ')*';
  var sLocalPart = sWord + '(\\x2e' + sWord + ')*';
  var sAddrSpec = sLocalPart + '\\x40' + sDomain; // complete RFC822 email address spec
  var sValidEmail = '^' + sAddrSpec + '$'; // as whole string

  var reValidEmail = new RegExp(sValidEmail);

  return reValidEmail.test(emailAddress);
}
</code></pre>


blocks|key|1773210|text|只需检查输入的电子邮件地址是否有效或未使用HTML。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773211|<input+type="email"/>|code-block|syntax|javascript|1773212|不需要编写用于验证的函数。|1773213|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>Simply check out if the entered email address is valid or not using HTML.</p>

<pre><code>&lt;input type="email"/&gt;
</code></pre>

<p>There isn't any need to write a function for validation.</p>


blocks|key|1558104|text|所有电子邮件地址都包含'at‘(即@)符号。测试必要条件：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1558105|email.includes('@')|code-block|syntax|javascript|1558106|或者，如果您需要支持IE/旧版浏览器：|1558107|email.indexOf('@')+>+0|1558108|不要为任何更复杂的事情而烦恼。即使您可以完美地确定一封电子邮件在RFC语法上是否有效，也不会告诉您它是否属于提供它的人。这才是真正重要的。|1558109|要测试这一点，请发送一条验证消息。|1558110|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>All email addresses contain an 'at' (i.e. @) symbol. Test that necessary condition:</p>
<pre><code>email.includes('@')
</code></pre>
<p>Or, if you need to support IE/older browsers:</p>
<pre><code>email.indexOf('@') &gt; 0
</code></pre>
<p>Don't bother with anything more complicated. Even if you could perfectly determine whether an email is RFC-syntactically valid, that wouldn't tell you whether it belongs to the person who supplied it. That's what really matters.</p>
<p>To test that, send a validation message.</p>


blocks|key|1773331|text|node-validator是这样做的：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1773332|/%5E(?:[\w\!\#\$\%25\&\'\*\%2B\-\/\=\?\%5E\`\{\%7C\}\~]%2B\.)*[\w\!\#\$\%25\&\'\*\%2B\-\/\=\?\%5E\`\{\%7C\}\~]%2B@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!\.)){0,61}[a-zA-Z0-9]?\.)%2B[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!$)){0,61}[a-zA-Z0-9]?)%7C(?:\[(?:(?:[01]?\d{1,2}%7C2[0-4]\d%7C25[0-5])\.){3}(?:[01]?\d{1,2}%7C2[0-4]\d%7C25[0-5])\]))$/|code-block|syntax|javascript|1773333|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/chriso/validator.js^0|0|E|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

<p>This is how <a href="https://github.com/chriso/validator.js" rel="noreferrer">node-validator</a> does it:</p>

<pre><code>/^(?:[\w\!\#\$\%\&amp;\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&amp;\'\*\+\-\/\=\?\^\`\{\|\}\~]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!\.)){0,61}[a-zA-Z0-9]?\.)+[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!$)){0,61}[a-zA-Z0-9]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/
</code></pre>


blocks|key|1773402|text|在验证器函数中使用以下代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773403|var+emailID+=+document.forms["formName"]["form+element+id"].value;
atpos+=+emailID.indexOf("@");
dotpos+=+emailID.lastIndexOf(".");
if+(atpos+<+1+%7C%7C+(+dotpos+-+atpos+<+2+))
{
++++alert("Please+enter+correct+email+ID")
++++return+false;
}|code-block|syntax|javascript|1773404|否则，您可以使用jQuery。内部规则定义：|offset|length|1773405|eMailId:+{
++++required:+true,
++++email:+true
}|1773406|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/JQuery^0|0|0|8|6|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@$I|X|J|Y|1|Z]]|A|$]]|$1|K|3|L|5|D|7|10|8|@]|9|@]|A|$E|F]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<p>Use this code inside your validator function:</p>

<pre><code>var emailID = document.forms["formName"]["form element id"].value;
atpos = emailID.indexOf("@");
dotpos = emailID.lastIndexOf(".");
if (atpos &lt; 1 || ( dotpos - atpos &lt; 2 ))
{
    alert("Please enter correct email ID")
    return false;
}
</code></pre>

<p>Else you can use <a href="http://en.wikipedia.org/wiki/JQuery" rel="noreferrer">jQuery</a>. Inside rules define:</p>

<pre><code>eMailId: {
    required: true,
    email: true
}
</code></pre>


blocks|key|1558254|text|微软在ASP.NET+MVC中提供的正则表达式是|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1558255|/%5E[\w-]%2B(\.[\w-]%2B)*@([a-z0-9-]%2B(\.[a-z0-9-]%2B)*?\.[a-z]{2,6}%7C(\d{1,3}\.){3}\d{1,3})(:\d{4})?$/|code-block|syntax|javascript|1558256|我把它贴在这里，以防它有缺陷--尽管它总是完美地满足我的需求。|1558257|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/ASP.NET_MVC_Framework^0|3|B|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

<p>The regular expression provided by Microsoft within <a href="http://en.wikipedia.org/wiki/ASP.NET_MVC_Framework" rel="noreferrer">ASP.NET MVC</a> is</p>

<pre><code>/^[\w-]+(\.[\w-]+)*@([a-z0-9-]+(\.[a-z0-9-]+)*?\.[a-z]{2,6}|(\d{1,3}\.){3}\d{1,3})(:\d{4})?$/
</code></pre>

<p>Which I post here in case it's flawed - though it's always been perfect for my needs.</p>


blocks|key|1773474|text|<pre>
**The+personal_info+part+contains+the+following+ASCII+characters.
1.Uppercase+(A-Z)+and+lowercase+(a-z)+English+letters.
2.Digits+(0-9).
3.Characters+!+#+$+%25+&+'+*+%2B+-+/+=+?+%5E+_+`+{+%7C+}+~
4.Character+.+(+period,+dot+or+fullstop)+provided+that+it+is+not+the+first+or+last+character+and+it+will+not+come+one+after+the+other.**
</pre>
*Example+of+valid+email+id*
<pre>
yoursite@ourearth.com
my.ownsite@ourearth.org
mysite@you.me.net
xxxx@gmail.com
xxxxxx@yahoo.com
</pre>
<pre>
xxxx.ourearth.com+[@+is+not+present]+
xxxx@.com.my+[+tld+(Top+Level+domain)+can+not+start+with+dot+"."+]
@you.me.net+[+No+character+before+@+]
xxxx123@gmail.b+[+".b"+is+not+a+valid+tld+]
xxxx@.org.org+[+tld+can+not+start+with+dot+"."+]
.xxxx@mysite.org+[+an+email+should+not+be+start+with+"."+]
xxxxx()*@gmail.com+[+here+the+regular+expression+only+allows+character,+digit,+underscore+and+dash+]
xxxx..1234@yahoo.com+[double+dots+are+not+allowed
</pre>
**javascript+mail+code**

++++function+ValidateEmail(inputText)
++++{
++++var+mailformat+=+/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/;
++++if(inputText.value.match(mailformat))
++++{
++++document.form1.text1.focus();
++++return+true;
++++}
++++else
++++{
++++alert("You+have+entered+an+invalid+email+address!");
++++document.form1.text1.focus();
++++return+false;
++++}
++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1773475|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>&lt;pre&gt;
**The personal_info part contains the following ASCII characters.
1.Uppercase (A-Z) and lowercase (a-z) English letters.
2.Digits (0-9).
3.Characters ! # $ % &amp; ' * + - / = ? ^ _ ` { | } ~
4.Character . ( period, dot or fullstop) provided that it is not the first or last character and it will not come one after the other.**
&lt;/pre&gt;
*Example of valid email id*
&lt;pre&gt;
yoursite@ourearth.com
my.ownsite@ourearth.org
mysite@you.me.net
xxxx@gmail.com
xxxxxx@yahoo.com
&lt;/pre&gt;
&lt;pre&gt;
xxxx.ourearth.com [@ is not present] 
xxxx@.com.my [ tld (Top Level domain) can not start with dot "." ]
@you.me.net [ No character before @ ]
xxxx123@gmail.b [ ".b" is not a valid tld ]
xxxx@.org.org [ tld can not start with dot "." ]
.xxxx@mysite.org [ an email should not be start with "." ]
xxxxx()*@gmail.com [ here the regular expression only allows character, digit, underscore and dash ]
xxxx..1234@yahoo.com [double dots are not allowed
&lt;/pre&gt;
**javascript mail code**

    function ValidateEmail(inputText)
    {
    var mailformat = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
    if(inputText.value.match(mailformat))
    {
    document.form1.text1.focus();
    return true;
    }
    else
    {
    alert("You have entered an invalid email address!");
    document.form1.text1.focus();
    return false;
    }
    }
</code></pre>


blocks|key|1773520|text|在JavaScript中非常简单。遵循以下代码。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1773521|function+validate(){
++++var+email+=+document.getElementById('Email');
++++var+filter+=+/%5E([a-zA-Z0-9_\.\-])%2B\@(([a-zA-Z0-9\-])%2B\.)%2B([a-zA-Z0-9]{2,4})%2B$/;

++++if+(!filter.test(email.value))
++++{
++++++++alert('Please+Enter+the+valid+email+address');
++++++++email.focus;
++++++++return+false;
++++}
++++else
{
++++++++return+true;
++++}|code-block|syntax|javascript|1773522|用于此的HTML代码：|1773523|form+name="form"
+++++enctype="multipart/form-data"
+++++name="form"
+++++action="register.php"
+++++method="POST"+onsubmit="return+validate();"+>
++++<input+type="text"+placeholder="Enter+ur+Email+Id"+id="Email"+name="Email"+/>
++++<input+type="submit"+id="submit"+value="save"+name="Like"+class="button"+/>
</form>|1773524|entityMap^0|1|A|0|0|4|4|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

<p>Very simple in <code>JavaScript</code>. follow this code.</p>

<pre><code>function validate(){
    var email = document.getElementById('Email');
    var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;

    if (!filter.test(email.value))
    {
        alert('Please Enter the valid email address');
        email.focus;
        return false;
    }
    else
{
        return true;
    }
</code></pre>

<p><code>HTML</code> code for this:</p>

<pre><code>form name="form"
     enctype="multipart/form-data"
     name="form"
     action="register.php"
     method="POST" onsubmit="return validate();" &gt;
    &lt;input type="text" placeholder="Enter ur Email Id" id="Email" name="Email" /&gt;
    &lt;input type="submit" id="submit" value="save" name="Like" class="button" /&gt;
&lt;/form&gt;
</code></pre>


blocks|key|1558337|text|我的一个同事和我分享了这个正则表达式。我非常喜欢它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1558338|function+isValidEmailAddress+(email)+{
++++var+validEmail+=+false;
++++if+(email)+{
++++++++email+=+email.trim().toLowerCase();
++++++++var+pattern+=+/%5E[\w-']%2B(\.[\w-']%2B)*@([a-zA-Z0-9]%2B[a-zA-Z0-9-]%2B(\.[a-zA-Z0-9-]%2B)*?\.[a-zA-Z]{2,6}%7C(\d{1,3}\.){3}\d{1,3})(:\d{4})?$/;
++++++++validEmail+=+pattern.exec(email);
++++}

++++return+validEmail;
}

if+(typeof+String.prototype.trim+!==+'function')+{
++++String.prototype.trim+=+function()+{
++++++++return+this.replace(/%5E\s%2B%7C\s%2B$/g,+'');
++++};
}|code-block|syntax|javascript|1558339|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>One of my coworker shared this regex with me. I like it a lot.</p>

<pre><code>function isValidEmailAddress (email) {
    var validEmail = false;
    if (email) {
        email = email.trim().toLowerCase();
        var pattern = /^[\w-']+(\.[\w-']+)*@([a-zA-Z0-9]+[a-zA-Z0-9-]+(\.[a-zA-Z0-9-]+)*?\.[a-zA-Z]{2,6}|(\d{1,3}\.){3}\d{1,3})(:\d{4})?$/;
        validEmail = pattern.exec(email);
    }

    return validEmail;
}

if (typeof String.prototype.trim !== 'function') {
    String.prototype.trim = function() {
        return this.replace(/^\s+|\s+$/g, '');
    };
}
</code></pre>


blocks|key|1773574|text|function+validatecontactEmail(email)+{+

+if+(/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/.test(email))++
++{++
++++return+(true)++
++}++

++++return+(false)++

}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1773575|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>function validatecontactEmail(email) { 

 if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(email))  
  {  
    return (true)  
  }  

    return (false)  

}
</code></pre>


blocks|key|1773602|text|以下是我用于前端电子邮件验证的函数。(正则表达式来自parsley.js)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773603|<!DOCTYPE+html>
<html>
<head>
++++<title>Our+Company</title>
++++<style>
++++++++.form-style+{
++++++++++++color:+#ccc;
++++++++}
++++</style>
</head>
<body>
++++<h1>Email+Validation+Form+Example</h1>
++++<input+type="text"+name="email"+id="emailInput"+class="form-style">
++++<script>
++++++++function+validateEmail(emailAddress)+{
++++++++++++var+regularExpression+=+/%5E((([a-z]%7C\d%7C[!#\$%25&'\*\%2B\-\/=\?\%5E_`{\%7C}~]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])%2B(\.([a-z]%7C\d%7C[!#\$%25&'\*\%2B\-\/=\?\%5E_`{\%7C}~]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])%2B)*)%7C((\x22)((((\x20%7C\x09)*(\x0d\x0a))?(\x20%7C\x09)%2B)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]%7C\x21%7C[\x23-\x5b]%7C[\x5d-\x7e]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])%7C(\\([\x01-\x09\x0b\x0c\x0d-\x7f]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20%7C\x09)*(\x0d\x0a))?(\x20%7C\x09)%2B)?(\x22)))@((([a-z]%7C\d%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])%7C(([a-z]%7C\d%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]%7C\d%7C-%7C\.%7C_%7C~%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]%7C\d%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)%2B(([a-z]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])%7C(([a-z]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]%7C\d%7C-%7C\.%7C_%7C~%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]%7C[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))){2,6}$/i;
+++++++++++++return+regularExpression.test(emailAddress);
++++++++}

++++++++function+showEmailValidationState(event)+{
++++++++++++if+(validateEmail(event.target.value))+{
++++++++++++++++document.getElementById("emailInput").style.color+=+'black';
++++++++++++}
++++++++}
++++document.getElementById("emailInput").addEventListener("keyup",+showEmailValidationState);
++++</script>
</body>
</html>|code-block|syntax|javascript|1773604|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Here is a function I use for front end email validation. (The Regular Expression came from parsley.js)</p>

<pre><code>&lt;!DOCTYPE html&gt;
&lt;html&gt;
&lt;head&gt;
    &lt;title&gt;Our Company&lt;/title&gt;
    &lt;style&gt;
        .form-style {
            color: #ccc;
        }
    &lt;/style&gt;
&lt;/head&gt;
&lt;body&gt;
    &lt;h1&gt;Email Validation Form Example&lt;/h1&gt;
    &lt;input type="text" name="email" id="emailInput" class="form-style"&gt;
    &lt;script&gt;
        function validateEmail(emailAddress) {
            var regularExpression = /^((([a-z]|\d|[!#\$%&amp;'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&amp;'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))){2,6}$/i;
             return regularExpression.test(emailAddress);
        }

        function showEmailValidationState(event) {
            if (validateEmail(event.target.value)) {
                document.getElementById("emailInput").style.color = 'black';
            }
        }
    document.getElementById("emailInput").addEventListener("keyup", showEmailValidationState);
    &lt;/script&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>


blocks|key|1773630|text|电子邮件的验证正则表达式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773631|var+rex_email+=+/%5E(([%5E<>()[\]\\.,;:\s@\"]%2B(\.[%5E<>()[\]\\.,;:\s@\"]%2B)*)%7C(\".%2B\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/;

if(email=="")+{
++++window.plugins.toast.showShortBottom(+"Please+enter+the+details.+",+function(a)+{
++++++++console.log('toast+success:+'+%2B+a);
++++},+function(b)+{+});
}+else+if(!rex_email.test(email))+{
++++window.plugins.toast.showShortBottom(+"Please+enter+the+valid+email+id.+",+function(a)+{
++++++++console.log('toast+success:+'+%2B+a);
++++},+function(b)+{+});
}|code-block|syntax|javascript|1773632|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Validation regex for email:</p>

<pre><code>var rex_email = /^(([^&lt;&gt;()[\]\\.,;:\s@\"]+(\.[^&lt;&gt;()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

if(email=="") {
    window.plugins.toast.showShortBottom( "Please enter the details. ", function(a) {
        console.log('toast success: ' + a);
    }, function(b) { });
} else if(!rex_email.test(email)) {
    window.plugins.toast.showShortBottom( "Please enter the valid email id. ", function(a) {
        console.log('toast success: ' + a);
    }, function(b) { });
}
</code></pre>


blocks|key|1558497|text|我知道这不是正则表达式，但不管怎样...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1558498|这是使用节点和npm包email-existence的示例，这是最终检查电子邮件是否存在以及其格式是否正确:)|offset|length|1558499|这将ping电子邮件，如果它正在响应，如果它没有得到响应，它将返回false或true。|1558500|function+doesEmailExist(email)+{
++++var+emailExistence+=+require('email-existence');
++++return+emailExistence.check(email,function+(err,status)+{
++++++++++++if+(status)+{
++++++++++++++++return+status;
++++++++++++}
++++++++++++else+{
++++++++++++++++throw+new+Error('Email+does+not+exist');
++++++++++++}
++++++++});
}|code-block|syntax|javascript|1558501|entityMap|0|LINK|mutability|MUTABLE|url|https://www.npmjs.com/package/email-existence^0|0|B|F|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@$D|W|E|X|1|Y]]|A|$]]|$1|F|3|G|5|6|7|Z|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|10|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<p>I know its not regex but any way...</p>

<p>This is example with node and npm package <a href="https://www.npmjs.com/package/email-existence" rel="nofollow">email-existence</a> this is ultimate checking if email exist and if its in the right form :)</p>

<p>This will ping the email if its responding if it got no response it will return false or else true.</p>

<pre><code>function doesEmailExist(email) {
    var emailExistence = require('email-existence');
    return emailExistence.check(email,function (err,status) {
            if (status) {
                return status;
            }
            else {
                throw new Error('Email does not exist');
            }
        });
}
</code></pre>


blocks|key|1773771|text|\b[a-z][\w\d_\.]%2B@\w%2B\.[a-z]{2}[a-z]?\.?[a-z]{,2}\s|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1773772|它允许：|unstyled|1773773|abcxyz123@qwert.com++++
abc123xyz@asdf.co.in+++
abc1_xyz1@gmail1.com+++
abc.xyz@gmail.com.in|1773774|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|L|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|I|3|-4|5|F|7|N|8|@]|9|@]|A|$]]]|J|$]]

<pre><code>\b[a-z][\w\d_\.]+@\w+\.[a-z]{2}[a-z]?\.?[a-z]{,2}\s
</code></pre>

<p>It allows:</p>

<pre><code>abcxyz123@qwert.com    
abc123xyz@asdf.co.in   
abc1_xyz1@gmail1.com   
abc.xyz@gmail.com.in
</code></pre>


blocks|key|1558595|text|最好的一个:D+(RFC友好&没有“太复杂”的错误)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1558596|function++++isMail(mail)
{
++++pattuser+=+/%5E([A-Z0-9_%25%2B\-!#$&'*\/=?%5E`{%7C}~]%2B\.?)*[A-Z0-9_%25%2B\-!#$&'*\/=?%5E`{%7C}~]%2B$/i;
++++pattdomain+=+/%5E([A-Z0-9-]%2B\.?)*[A-Z0-9-]%2B(\.[A-Z]{2,9})%2B$/i;

++++tab+=+mail.split("@");
++++if+(tab.length+!=+2)
++++++++return+false;
++++return+(pattuser.test(tab[0])+&&+pattdomain.test(tab[1]));
}|code-block|syntax|javascript|1558597|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>the best one :D (RFC-friendly &amp; no error "too complex") :</p>

<pre><code>function    isMail(mail)
{
    pattuser = /^([A-Z0-9_%+\-!#$&amp;'*\/=?^`{|}~]+\.?)*[A-Z0-9_%+\-!#$&amp;'*\/=?^`{|}~]+$/i;
    pattdomain = /^([A-Z0-9-]+\.?)*[A-Z0-9-]+(\.[A-Z]{2,9})+$/i;

    tab = mail.split("@");
    if (tab.length != 2)
        return false;
    return (pattuser.test(tab[0]) &amp;&amp; pattdomain.test(tab[1]));
}
</code></pre>


blocks|key|1773856|text|此正则表达式可防止重复的域名，如abc@abc.com.com，它将只允许域名的两倍，如abc@abc.co.in。它也不允许像123abc@abc.com那样从number进行状态|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773857|regexp:+/%5E([a-zA-Z])%2B([a-zA-Z0-9_.%2B-])%2B\@(([a-zA-Z])%2B\.%2B?(com%7Cco%7Cin%7Corg%7Cnet%7Cedu%7Cinfo%7Cgov%7Cvekomy))\.?(com%7Cco%7Cin%7Corg%7Cnet%7Cedu%7Cinfo%7Cgov)?$/,++|code-block|syntax|javascript|1773858|一切顺利！|1773859|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>This regexp prevents duplicate domain names like abc@abc.com.com.com.com, it will allow only domain two time like abc@abc.co.in. It also does not allow statring from number like 123abc@abc.com  </p>

<pre><code>regexp: /^([a-zA-Z])+([a-zA-Z0-9_.+-])+\@(([a-zA-Z])+\.+?(com|co|in|org|net|edu|info|gov|vekomy))\.?(com|co|in|org|net|edu|info|gov)?$/,  
</code></pre>

<p>All The Best !!!!!</p>


blocks|key|1773881|text|电子邮件Id的简单正则表达式|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773882|+String+EMAIL_PATTERN+="%5E(([%5E<>()\[\]\.,;:\s@\"]%2B(\.[%5E<>()\[\]\.,;:\s@\"]%2B)*)%7C(\".%2B\"))@(([%5E<>()[\]\.,;:\s@\"]%2B\.)%2B[%5E<>()[\]\.,;:\s@\"]{2,})$";|code-block|syntax|javascript|1773883|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Simple regex for email-Id</p>

<pre><code> String EMAIL_PATTERN ="^(([^&lt;&gt;()\[\]\.,;:\s@\"]+(\.[^&lt;&gt;()\[\]\.,;:\s@\"]+)*)|(\".+\"))@(([^&lt;&gt;()[\]\.,;:\s@\"]+\.)+[^&lt;&gt;()[\]\.,;:\s@\"]{2,})$";
</code></pre>


blocks|key|1773925|text|使用正则表达式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773926|+/%5E[a-z][a-zA-Z0-9_.]*(\.[a-zA-Z][a-zA-Z0-9_.]*)?@[a-z][a-zA-Z-0-9]*\.[a-z]%2B(\.[a-z]%2B)?$/|code-block|syntax|javascript|1773927|示例：|1773928|function+validateEmail(email)+{
++++var+re+=+/%5E[a-z][a-zA-Z0-9_.]*(\.[a-zA-Z][a-zA-Z0-9_.]*)?@[a-z][a-zA-Z-0-9]*\.[a-z]%2B(\.[a-z]%2B)?$/;
++++return+re.test(email);
}|1773929|它应该只允许@，。，_|1773930|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

<p>Use the regular expression:</p>

<pre class="lang-none prettyprint-override"><code> /^[a-z][a-zA-Z0-9_.]*(\.[a-zA-Z][a-zA-Z0-9_.]*)?@[a-z][a-zA-Z-0-9]*\.[a-z]+(\.[a-z]+)?$/
</code></pre>

<p>Example:</p>

<pre><code>function validateEmail(email) {
    var re = /^[a-z][a-zA-Z0-9_.]*(\.[a-zA-Z][a-zA-Z0-9_.]*)?@[a-z][a-zA-Z-0-9]*\.[a-z]+(\.[a-z]+)?$/;
    return re.test(email);
}
</code></pre>

<p>It should allow only  @ ,  . , _</p>


blocks|key|1773976|text|我将@mevius和@Boldewyn代码混合在一起，创建了使用JavaScript验证电子邮件的终极代码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1773977|​|1773978|function+ValidateEmail(email){
+
++var+re+=+/%5E(([%5E<>()\[\]\\.,;:\s@"]%2B(\.[%5E<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/;
+
++var+input+=+document.createElement('input');
+
++input.type+=+'email';
++input.value+=+email;
+
++return+typeof+input.checkValidity+==+'function'+?+input.checkValidity()+:+re.test(email);
+
}|code-block|syntax|javascript|1773979|1773980|我已经在我的博客here上分享了这段代码。|offset|length|1773981|entityMap|0|LINK|mutability|MUTABLE|url|http://mycodingtricks.com/snippets/javascript/javascript-regex-email-validation/^0|0|0|0|0|8|4|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|W|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|X|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Z|8|@]|9|@$L|10|M|11|1|12]]|A|$]]|$1|N|3|-4|5|6|7|13|8|@]|9|@]|A|$]]]|O|$P|$5|Q|R|S|A|$T|U]]]]

<p>I've mixed @mevius and @Boldewyn Code to Create this ultimate code for email verification using JavaScript.</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function ValidateEmail(email){
 
  var re = /^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
 
  var input = document.createElement('input');
 
  input.type = 'email';
  input.value = email;
 
  return typeof input.checkValidity == 'function' ? input.checkValidity() : re.test(email);
 
}</code></pre>
</div>
</div>
</p>

<p>I have shared this code on my blog <a href="http://mycodingtricks.com/snippets/javascript/javascript-regex-email-validation/" rel="noreferrer">here</a>.</p>


blocks|key|1774034|text|如果您正在使用ng-pattern和material，这就可以完成这项工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774035|vm.validateEmail+=+'([a-zA-Z0-9_.]{1,})((@[a-zA-Z]{2,})[\\\.]([a-zA-Z]{2}%7C[a-zA-Z]{3}))';|code-block|syntax|javascript|1774036|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>If you are using ng-pattern and material this does the job. </p>

<pre><code>vm.validateEmail = '([a-zA-Z0-9_.]{1,})((@[a-zA-Z]{2,})[\\\.]([a-zA-Z]{2}|[a-zA-Z]{3}))';
</code></pre>


blocks|key|1558910|text|无论是谁在使用@pvl解决方案，并希望它传递ESLint+Prefer-template，那么这里有一个版本，其中我使用了模板文字而不是字符串连接。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1558911|validateEmail(email)+{
++++let+sQtext+=+'[%5E\\x0d\\x22\\x5c\\x80-\\xff]';
++++let+sDtext+=+'[%5E\\x0d\\x5b-\\x5d\\x80-\\xff]';
++++let+sAtom+=+'[%5E\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]%2B';
++++let+sQuotedPair+=+'\\x5c[\\x00-\\x7f]';
++++let+sDomainLiteral+=+`\\x5b(${sDtext}%7C${sQuotedPair})*\\x5d`;
++++let+sQuotedString+=+`\\x22(${sQtext}%7C${sQuotedPair})*\\x22`;
++++let+sDomainRef+=+sAtom;
++++let+sSubDomain+=+`(${sDomainRef}%7C${sDomainLiteral})`;
++++let+sWord+=+`(${sAtom}%7C${sQuotedString})`;
++++let+sDomain+=+`${sSubDomain}(\\x2e${sSubDomain})*`;
++++let+sLocalPart+=+`${sWord}(\\x2e${sWord})*`;
++++let+sAddrSpec+=+`${sLocalPart}\\x40${sDomain}`;+//+complete+RFC822+email+address+spec
++++let+sValidEmail+=+`%5E${sAddrSpec}$`;+//+as+whole+string

++++let+reValidEmail+=+new+RegExp(sValidEmail);

++++return+reValidEmail.test(email);
}|code-block|syntax|javascript|1558912|entityMap|0|LINK|mutability|MUTABLE|url|http://eslint.org/docs/rules/prefer-template^0|M|M|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

<p>Whoever is using @pvl solution and wants it to pass <a href="http://eslint.org/docs/rules/prefer-template" rel="nofollow noreferrer">ESLint Prefer-template</a> then here's a version where I used template literals instead of string concatenation.</p>

<pre><code>validateEmail(email) {
    let sQtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
    let sDtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
    let sAtom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
    let sQuotedPair = '\\x5c[\\x00-\\x7f]';
    let sDomainLiteral = `\\x5b(${sDtext}|${sQuotedPair})*\\x5d`;
    let sQuotedString = `\\x22(${sQtext}|${sQuotedPair})*\\x22`;
    let sDomainRef = sAtom;
    let sSubDomain = `(${sDomainRef}|${sDomainLiteral})`;
    let sWord = `(${sAtom}|${sQuotedString})`;
    let sDomain = `${sSubDomain}(\\x2e${sSubDomain})*`;
    let sLocalPart = `${sWord}(\\x2e${sWord})*`;
    let sAddrSpec = `${sLocalPart}\\x40${sDomain}`; // complete RFC822 email address spec
    let sValidEmail = `^${sAddrSpec}$`; // as whole string

    let reValidEmail = new RegExp(sValidEmail);

    return reValidEmail.test(email);
}
</code></pre>


blocks|key|1558948|text|验证电子邮件地址的正则表达式|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1558949|[a-z0-9!#$%25&'*%2B/=?%5E_`{%7C}~-]%2B(?:\.[a-z0-9!#$%25&'*%2B/=?%5E_`{%7C}~-]%2B)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)%2B[a-z0-9](?:[a-z0-9-]*[a-z0-9])%2B|code-block|syntax|javascript|1558950|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Regex for validating email address</p>

<pre><code>[a-z0-9!#$%&amp;'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&amp;'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])+
</code></pre>


blocks|key|1558999|text|在nodeJS中，您还可以使用验证器节点模块，并像这样简单地使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1559000|使用npm+Install+validator安装库|1559001|var+validator+=+require('validator');

validator.isEmail('foo@bar.com');+//=>+true+|code-block|syntax|javascript|1559002|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>In nodeJS you can also use validator node module and simply use like that </p>

<p>Install the library with npm install validator</p>

<pre><code>var validator = require('validator');

validator.isEmail('foo@bar.com'); //=&gt; true 
</code></pre>


blocks|key|1774291|text|如果将正则表达式定义为字符串，则需要对所有反斜杠进行转义，因此应该使用'\w‘而不是'\w’。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774292|或者，将其定义为正则表达式：|1774293|var+pattern+=+/%5E\w%2B@[a-zA-Z_]%2B?\.[a-zA-Z]{2,3}$/;+|code-block|syntax|javascript|1774294|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>If you define your regular expression as a string then all backslashes need to be escaped, so instead of '\w' you should have '\w'.</p>

<p>Alternatively, define it as a regular expression:</p>

<pre><code>var pattern = /^\w+@[a-zA-Z_]+?\.[a-zA-Z]{2,3}$/; 
</code></pre>


blocks|key|1774339|text|这里编写了一些复杂的RegEx，也可以正常工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774340|我测试了这个，它也可以工作：|1774341|[a-zA-Z0-9._]%2B[@]%2B[a-zA-Z0-9]%2B[.]%2B[a-zA-Z]{2,6}|code-block|syntax|javascript|1774342|请在这里进行测试：http://www.regextester.com/?fam=97334|offset|length|1774343|希望这能有所帮助。|1774344|entityMap|0|LINK|mutability|MUTABLE|url|http://www.regextester.com/?fam=97334^0|0|0|0|9|11|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@$K|10|L|11|1|12]]|A|$]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

<p>There are some complex RegEx written here, that also works.</p>

<p>I tested this one and it works too:</p>

<pre><code>[a-zA-Z0-9._]+[@]+[a-zA-Z0-9]+[.]+[a-zA-Z]{2,6}
</code></pre>

<p>Please test this here : <a href="http://www.regextester.com/?fam=97334" rel="nofollow noreferrer">http://www.regextester.com/?fam=97334</a></p>

<p>Hope this helps.</p>


blocks|key|1774430|text|我想添加一个关于非ASCII字符的简短说明。Rnevius's+(和co.)解决方案很出色，但它允许添加西里尔语，日语，表情符号和其他unicode符号，这可能会受到一些服务器的限制。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774431|下面的代码将打印true，尽管它包含UTF-8字符Ё。|offset|length|style|CODE|1774432|​|1774433|console.log+(/%5E(([%5E<>()\[\]\\.,;:\s@"]%2B(\.[%5E<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/.test+('Ё@example.org'))|code-block|syntax|javascript|1774434|1774435|在我的例子中，所有非ASCII符号都被禁止，所以我修改了原始表达式，以排除U%2B007F以上的所有字符：|1774436|1774437|/%5E(([%5E\u0080-\uffff<>()\[\]\\.,;:\s@"]%2B(\.[%5E\u0080-\uffff<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/|1774438|1774439|也许这会帮助某人防止不受欢迎的行为。|1774440|entityMap^0|0|8|4|P|1|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@$D|11|E|12|F|G]|$D|13|E|14|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|15|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|16|8|@]|9|@]|A|$M|N]]|$1|O|3|I|5|6|7|17|8|@]|9|@]|A|$]]|$1|P|3|Q|5|6|7|18|8|@]|9|@]|A|$]]|$1|R|3|I|5|6|7|19|8|@]|9|@]|A|$]]|$1|S|3|T|5|L|7|1A|8|@]|9|@]|A|$M|N]]|$1|U|3|I|5|6|7|1B|8|@]|9|@]|A|$]]|$1|V|3|W|5|6|7|1C|8|@]|9|@]|A|$]]|$1|X|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]]|Y|$]]

<p>I'd like to add a short note about non-ASCII characters. Rnevius's (and co.) solution is brilliant, but it allows to add Cyrillic, Japanese, Emoticons and other unicode symbols which may be restricted by some servers.</p>

<p>The code below will print <code>true</code> though it contains UTF-8 character <code>Ё</code>.</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>console.log (/^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/.test ('Ё@example.org'))</code></pre>
</div>
</div>
</p>

<p>In my case all non-ASCII symbols are prohibited so I have modified the original expression to exclude all characters above U+007F:</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>/^(([^\u0080-\uffff&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^\u0080-\uffff&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/</code></pre>
</div>
</div>
</p>

<p>Maybe this will help someone to prevent undesired behaviour.</p>


blocks|key|1774496|text|创建一个函数来使用JavaScript中的正则表达式来测试任何字符串与电子邮件的模式如何，因为我们知道电子邮件地址在不同的地区可能会有很大的不同，比如在英国和澳大利亚，它通常以.co.uk或.com.au结尾，所以我也尝试涵盖这些，同时检查字符串是否传递给该函数，类似于：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1774497|var+isEmail+=+function(str)+{
++return+typeof+str==='string'+&&+/%5E[\w%2B\d%2B._]%2B\@[\w%2B\d%2B_%2B]%2B\.[\w%2B\d%2B._]{2,8}$/.test(str);
}|code-block|syntax|javascript|1774498|并检查是否为如下所示的电子邮件：|1774499|isEmail('alex@example.com');+//true
isEmail('alireza@test.co.uk');+//true
isEmail('peter.example@yahoo.com.au');+//true
isEmail('alex@example.com');+//true
isEmail('peter_123@news.com');+//true
isEmail('hello7___@ca.com.pt');+//true
isEmail('example@example.co');+//true
isEmail('hallo@example.coassjj#sswzazaaaa');+//false
isEmail('hallo2ww22@example....caaaao');+//false|1774500|entityMap^0|2G|6|2N|7|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

<p>How about creating a function which will test any string against emails' pattern using regular expression in JavaScript, as we know email addresses can be quite different in different regions, like in UK and Australia it usually ends up with <code>.co.uk</code> or <code>.com.au</code>, so I tried to cover those as well, also check if the string passed to the function, something like this:</p>

<pre><code>var isEmail = function(str) {
  return typeof str==='string' &amp;&amp; /^[\w+\d+._]+\@[\w+\d+_+]+\.[\w+\d+._]{2,8}$/.test(str);
}
</code></pre>

<p>and check if it's email like below:</p>

<pre><code>isEmail('alex@example.com'); //true
isEmail('alireza@test.co.uk'); //true
isEmail('peter.example@yahoo.com.au'); //true
isEmail('alex@example.com'); //true
isEmail('peter_123@news.com'); //true
isEmail('hello7___@ca.com.pt'); //true
isEmail('example@example.co'); //true
isEmail('hallo@example.coassjj#sswzazaaaa'); //false
isEmail('hallo2ww22@example....caaaao'); //false
</code></pre>


blocks|key|1774515|text|ES6示例|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774516|const+validateEmail=(email)=>+/%5E(([%5E<>()\[\]\\.,;:\s@"]%2B(\.[%5E<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/.test(email);|code-block|syntax|javascript|1774517|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>ES6 sample</p>

<pre><code>const validateEmail=(email)=&gt; /^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/.test(email);
</code></pre>


blocks|key|1559341|text|现在，ReactNative版本0.46使用以下代码进行电子邮件验证。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1559342|+validateEmail+=+(email)+=>+{
+++++var+re+=+/%5E(([%5E<>()\[\]\\.,;:\s@"]%2B(\.[%5E<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/;
+++++if+(re.test(email))+{
+++++}+else+{
+++++++alert('email:+'+%2B+"Please+enter+valid+emailID.")
+++++}
+}|code-block|syntax|javascript|1559343|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Now ReactNative Version 0.46 Use Below code for email Validation.</p>

<pre><code> validateEmail = (email) =&gt; {
     var re = /^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
     if (re.test(email)) {
     } else {
       alert('email: ' + "Please enter valid emailID.")
     }
 }
</code></pre>


blocks|key|1774543|text|您也可以尝试|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774544|var+string+=+"hmharsh3@gmail.com"
var+exp+=+/(\w(=?@)\w%2B\.{1}[a-zA-Z]{2,})/i
alert(exp.test(string))|code-block|syntax|javascript|1774545|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>You can also try</p>

<pre><code>var string = "hmharsh3@gmail.com"
var exp = /(\w(=?@)\w+\.{1}[a-zA-Z]{2,})/i
alert(exp.test(string))
</code></pre>


blocks|key|1559387|text|Regex更新2018！尝尝这个|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1559388|let+val+=+'email@domain.com';
if(/%5E[a-z0-9][a-z0-9-_\.]%2B@([a-z]%7C[a-z0-9]?[a-z0-9-]%2B[a-z0-9])\.[a-z0-9]{2,10}(?:\.[a-z]{2,10})?$/.test(val))+{
+++console.log('passed');
}|code-block|syntax|javascript|1559389|typscript版本完成|1559390|//
export+const+emailValid+=+(val:string):boolean+=>+/%5E[a-z0-9][a-z0-9-_\.]%2B@([a-z]%7C[a-z0-9]?[a-z0-9-]%2B[a-z0-9])\.[a-z0-9]{2,10}(?:\.[a-z]{2,10})?$/.test(val);|1559391|更多信息https://git.io/vhEfc|offset|length|1559392|entityMap|0|LINK|mutability|MUTABLE|url|https://git.io/vhEfc^0|0|0|0|0|4|K|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@$M|11|N|12|1|13]]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

<p>Regex update 2018! try this</p>

<pre><code>let val = 'email@domain.com';
if(/^[a-z0-9][a-z0-9-_\.]+@([a-z]|[a-z0-9]?[a-z0-9-]+[a-z0-9])\.[a-z0-9]{2,10}(?:\.[a-z]{2,10})?$/.test(val)) {
   console.log('passed');
}
</code></pre>

<p>typscript version complete</p>

<pre><code>//
export const emailValid = (val:string):boolean =&gt; /^[a-z0-9][a-z0-9-_\.]+@([a-z]|[a-z0-9]?[a-z0-9-]+[a-z0-9])\.[a-z0-9]{2,10}(?:\.[a-z]{2,10})?$/.test(val);
</code></pre>

<p>more info <a href="https://git.io/vhEfc" rel="noreferrer">https://git.io/vhEfc</a></p>


blocks|key|1559403|text|+<input+type="email"+class="form-control"+required="required"+placeholder="Email+Address"+name="Email"+id="Email"+autocomplete="Email">
+<button+class="btn-1+shadow-0+full-width"+type="button"+id="register">Register+account</button>|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1559404|+$("#register").click(function(){+++++++
++++var+rea+=+/%5E[a-zA-Z0-9.!#$%25&'*%2B/=?%5E_`{%7C}~-]%2B@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;
++++var+Email+=+$("#Email").val();
++++var+x+=+rea.test(Email);
++++if+(!x)+{
++++++++alert('Type+Your+valid+Email');
++++++++return+false;
++++}+++++++++++
+</script>|1559405|unstyled|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|6|7|J|8|@]|9|@]|A|$B|C]]|$1|F|3|-4|5|G|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code> &lt;input type="email" class="form-control" required="required" placeholder="Email Address" name="Email" id="Email" autocomplete="Email"&gt;
 &lt;button class="btn-1 shadow-0 full-width" type="button" id="register"&gt;Register account&lt;/button&gt;
</code></pre>

<p>   </p>

<pre><code> $("#register").click(function(){       
    var rea = /^[a-zA-Z0-9.!#$%&amp;'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;
    var Email = $("#Email").val();
    var x = rea.test(Email);
    if (!x) {
        alert('Type Your valid Email');
        return false;
    }           
 &lt;/script&gt;
</code></pre>


blocks|key|1559422|text|下面是一个简单的正则表达式，它只检查电子邮件的基本格式，例如X@Y.C|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1559423|\S%2B@\S%2B\.\S%2B|1559424|entityMap^0|U|5|0|0|C|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

<p>Here's a simple  regex that would just check for the basic format of an email e.g., <code>X@Y.C</code>:</p>

<p><code>\S+@\S+\.\S+</code></p>


blocks|key|1774683|text|这是由数以千计的网站使用的官方Rails指南建议的验证的JavaScript翻译：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774684|/%5E([%5E@\s]%2B)@((?:[-a-z0-9]%2B\.)%2B[a-z]{2,})$/i|code-block|syntax|javascript|1774685|相对简单，但针对大多数常见错误进行测试。|1774686|在数千封电子邮件的数据集上进行测试，它没有假阴性/阳性。|1774687|示例用法：|1774688|const+emailRegex+=+/%5E([%5E@\s]%2B)@((?:[-a-z0-9]%2B\.)%2B[a-z]{2,})$/i;

emailRegex.test('email@example.com');++++//+true

//+Multi-word+domains
emailRegex.test('email@example.co.uk');++//+true
emailRegex.test('email@mail.gmail.com');+//+true

//+Valid+special+characters
emailRegex.test('unusual%2Bbut%2Bvalid%2Bemail1900=/!#$%25&\'*%2B-/=?%5E_`.{%7C}~@example.com')+//+true

//+Trailing+dots
emailRegex.test('email@example.co.uk.');+//+false

//+No+domain
emailRegex.test('email@example');++++++++//+false

//+Leading+space
emailRegex.test('+email@example.com');+++//+false

//+Trailing+space
emailRegex.test('email@example.com+');+++//+false

//+Incorrect+domains
emailRegex.test('email@example,com+');+++//+false

//+Other+invalid+emails
emailRegex.test('invalid.email.com')++++++++//+false
emailRegex.test('invalid@email@domain.com')+//+false
emailRegex.test('email@example..com')+++++++//+false|1774689|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>This is a JavaScript translation of the validation suggested by the official Rails guide used by thousands of websites:</p>

<pre><code>/^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i
</code></pre>

<p>Relatively simple but tests against most common errors.</p>

<p>Tested on a dataset of thousands of emails and it had zero false negatives/positives.</p>

<p>Example usage:</p>

<pre><code>const emailRegex = /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i;

emailRegex.test('email@example.com');    // true

// Multi-word domains
emailRegex.test('email@example.co.uk');  // true
emailRegex.test('email@mail.gmail.com'); // true

// Valid special characters
emailRegex.test('unusual+but+valid+email1900=/!#$%&amp;\'*+-/=?^_`.{|}~@example.com') // true

// Trailing dots
emailRegex.test('email@example.co.uk.'); // false

// No domain
emailRegex.test('email@example');        // false

// Leading space
emailRegex.test(' email@example.com');   // false

// Trailing space
emailRegex.test('email@example.com ');   // false

// Incorrect domains
emailRegex.test('email@example,com ');   // false

// Other invalid emails
emailRegex.test('invalid.email.com')        // false
emailRegex.test('invalid@email@domain.com') // false
emailRegex.test('email@example..com')       // false
</code></pre>


blocks|key|1774719|text|我写了一个与JavaScript的filter_var($value,+FILTER_VALIDATE_EMAIL)实现完全兼容的PHP验证器。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1774720|https://github.com/mpyw/FILTER_VALIDATE_EMAIL.js|1774721|import+validateEmail+from+'filter-validate-email'

const+value+=+'...'
const+result+=+validateEmail(value)|code-block|syntax|javascript|1774722|等同于：|1774723|<?php

$value+=+'...';
$result+=+(bool)filter_var($value,+FILTER_VALIDATE_EMAIL,+FILTER_FLAG_EMAIL_UNICODE);|1774724|entityMap|0|LINK|mutability|MUTABLE|url^0|H|15|0|0|1C|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|10|8|@]|D|@$9|11|A|12|1|13]]|E|$]]|$1|H|3|I|5|J|7|14|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|15|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|16|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|R|$S|$5|T|U|V|E|$W|G]]]]

<p>I wrote a JavaScript email validator which is fully compatile with PHP's <code>filter_var($value, FILTER_VALIDATE_EMAIL)</code> implementation.</p>

<p><a href="https://github.com/mpyw/FILTER_VALIDATE_EMAIL.js" rel="nofollow noreferrer">https://github.com/mpyw/FILTER_VALIDATE_EMAIL.js</a></p>

<pre><code>import validateEmail from 'filter-validate-email'

const value = '...'
const result = validateEmail(value)
</code></pre>

<p>is equivalent to:</p>

<pre><code>&lt;?php

$value = '...';
$result = (bool)filter_var($value, FILTER_VALIDATE_EMAIL, FILTER_FLAG_EMAIL_UNICODE);
</code></pre>


blocks|key|1774743|text|function+ValidateEmail(mail)+
{
++if+(/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/.test(myForm.emailAddr.value))
++{
++++return+(true)
++}
++alert("You+have+entered+an+invalid+email+address!")
++return+(false)
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1774744|参考网址：https://www.w3resource.com/javascript/form/email-validation.php|unstyled|offset|length|1774745|entityMap|0|LINK|mutability|MUTABLE|url|https://www.w3resource.com/javascript/form/email-validation.php^0|0|5|1R|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@$G|S|H|T|1|U]]|A|$]]|$1|I|3|-4|5|F|7|V|8|@]|9|@]|A|$]]]|J|$K|$5|L|M|N|A|$O|P]]]]

<pre><code>function ValidateEmail(mail) 
{
  if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(myForm.emailAddr.value))
  {
    return (true)
  }
  alert("You have entered an invalid email address!")
  return (false)
}
</code></pre>

<p>Ref URL: <a href="https://www.w3resource.com/javascript/form/email-validation.php" rel="nofollow noreferrer">https://www.w3resource.com/javascript/form/email-validation.php</a></p>


blocks|key|1774757|text|这对我来说很有效：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1774758|function+Email(mail)
{
+if+(/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/.test(myForm.emailAddr.value))
++{
++++return+(true)
++}
++++alert("Invalid+email+address!")
++++return+(false)
}|code-block|syntax|javascript|1774759|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>This works for me:</p>

<pre><code>function Email(mail)
{
 if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(myForm.emailAddr.value))
  {
    return (true)
  }
    alert("Invalid email address!")
    return (false)
}
</code></pre>


blocks|key|1559557|text|您还可以使用RegExp|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1559558|function+validateEmail(str)+{
++++return+new+RegExp(/([\w\.\-_]%2B)?\w%2B@[\w-_]%2B(\.\w%2B){1,}/,+'igm').test(str);
}|code-block|syntax|javascript|1559559|有关更多信息，请参阅Regular+Expressions+guide+on+MDN。|1559560|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp|1|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions^0|6|6|6|6|0|0|0|A|W|1|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@]|D|@$9|14|A|15|1|16]]|E|$]]|$1|M|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]|U|$5|P|Q|R|E|$S|V]]]]

<p>You could also use <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp" rel="nofollow noreferrer"><code>RegExp</code></a>:</p>
<pre><code>function validateEmail(str) {
    return new RegExp(/([\w\.\-_]+)?\w+@[\w-_]+(\.\w+){1,}/, 'igm').test(str);
}
</code></pre>
<p>See the <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions" rel="nofollow noreferrer">Regular Expressions guide on MDN</a> for more info.</p>


blocks|key|1774814|text|您可以使用https://github.com/chriso/validator.js并简单地执行以下操作：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1774815|var+validator+=+require('validator');

validator.isEmail('foo@bar.com');+//=>+true|code-block|syntax|javascript|1774816|请注意，这可以在客户端上工作。|1774817|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/chriso/validator.js^0|5|12|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

<p>You cold use <a href="https://github.com/chriso/validator.js" rel="nofollow noreferrer">https://github.com/chriso/validator.js</a> and simply do:</p>

<pre><code>var validator = require('validator');

validator.isEmail('foo@bar.com'); //=&gt; true
</code></pre>

<p>Note that this can work on the client.</p>


blocks|key|1559643|text|我是这样做的。我使用match()来检查标准的电子邮件模式，并在输入文本中添加一个类来相应地通知用户。希望这能有所帮助！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1559644|​|1559645|$(document).ready(function(){
++$('#submit').on('click',+function(){
++++++var+email+=+$('#email').val();
++++++var+pat+=+/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/;
++++++if+(email.match(pat)){
++++++++$('#email')
++++++++++.addClass('input-valid');
++++++++return+false;
++++++}+else+{
++++++++$('#email')
++++++++	.addClass('input-error')
++++++++++.val('');
++++++++return+false;
++++++}
++});
});|code-block|syntax|javascript|1559646|.input-error+{
++border:+1px+solid+red;
++color:+red;
}

.input-valid+{
++border:+1px+solid+green;
++color:+green;
}|1559647|<script+src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<form>
++++<input+type="text"+id="email"+placeholder="name@service.xx"+class="">
++++<input+type="submit"+id="submit"+value="Send"/>
</form>|1559648|1559649|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|R|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|K|3|L|5|F|7|T|8|@]|9|@]|A|$G|H]]|$1|M|3|C|5|6|7|U|8|@]|9|@]|A|$]]|$1|N|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|O|$]]

<p>Here's how I do it. I'm using match() to check for the standard email pattern and I'm adding a class to the input text to notify the user accordingly. Hope that helps!</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>$(document).ready(function(){
  $('#submit').on('click', function(){
      var email = $('#email').val();
      var pat = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
      if (email.match(pat)){
        $('#email')
          .addClass('input-valid');
        return false;
      } else {
        $('#email')
        	.addClass('input-error')
          .val('');
        return false;
      }
  });
});</code></pre>
<pre class="snippet-code-css lang-css prettyprint-override"><code>.input-error {
  border: 1px solid red;
  color: red;
}

.input-valid {
  border: 1px solid green;
  color: green;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"&gt;&lt;/script&gt;
&lt;form&gt;
    &lt;input type="text" id="email" placeholder="name@service.xx" class=""&gt;
    &lt;input type="submit" id="submit" value="Send"/&gt;
&lt;/form&gt;</code></pre>
</div>
</div>
</p>


blocks|key|1774948|text|这是我的电子邮件验证器版本。这段代码是用面向对象的编程完成的，并用静态方法实现为一个类。您将发现两个版本的验证器:+strict(EmailValidator.validate)和kind(EmailValidator.validateKind)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1774949|第一个函数在电子邮件无效时抛出错误，否则返回电子邮件。第二个返回布尔值，表示电子邮件是否有效。在大多数情况下，我更喜欢严格版本。|1774950|export+class+EmailValidator+{
++++/**
+++++*+@param+{string}+email
+++++*+@return+{string}
+++++*+@throws+{Error}
+++++*/
++++static+validate(email)+{
++++++++email+=+this.prepareEmail(email);

++++++++const+isValid+=+this.validateKind(email);

++++++++if+(isValid)
++++++++++++return+email;

++++++++throw+new+Error(`Got+invalid+email:+${email}.`);
++++}

++++/**
+++++*+@param+{string}+email
+++++*+@return+{boolean}
+++++*/
++++static+validateKind(email)+{
++++++++email+=+this.prepareEmail(email);

++++++++const+regex+=+this.getRegex();

++++++++return+regex.test(email);
++++}

++++/**
+++++*+@return+{RegExp}
+++++*+@private
+++++*/
++++static+getRegex()+{
++++++++return+/%5E(([%5E<>()\[\]\\.,;:\s@"]%2B(\.[%5E<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/;
++++}

++++/**
+++++*+@param+{string}+email
+++++*+@return+{string}
+++++*+@private
+++++*/
++++static+prepareEmail(email)+{
++++++++return+String(email).toLowerCase();
++++}
}|code-block|syntax|javascript|1774951|要验证电子邮件，您可以按照以下方式操作：|1774952|//+First+way.

try+{
++++EmailValidator.validate('balovbohdan@gmail.com');
}+catch+(e)+{
++++console.error(e.message);
}|1774953|//+Second+way.

const+email+=+'balovbohdan@gmail.com';
const+isValid+=+EmailValidator.validateKind(email);

if+(isValid)
++++console.log(`Email+is+valid:+${email}.`);
else
++++console.log(`Email+is+invalid:+${email}.`);|1774954|entityMap^0|1T|N|2N|R|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|11|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|J|7|13|8|@]|D|@]|E|$K|L]]|$1|S|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|T|$]]

<p>There is my version of an email validator. This code is done with object-oriented programming and realized as a class with static methods. You will find two versions of the validators: strict(<code>EmailValidator.validate</code>) and kind(<code>EmailValidator.validateKind</code>).</p>

<p>The first throws an error if an email is invalid and returns email otherwise. The second returns Boolean value that says if an email is valid. I prefer the strict version in most of the cases.</p>

<pre><code>export class EmailValidator {
    /**
     * @param {string} email
     * @return {string}
     * @throws {Error}
     */
    static validate(email) {
        email = this.prepareEmail(email);

        const isValid = this.validateKind(email);

        if (isValid)
            return email;

        throw new Error(`Got invalid email: ${email}.`);
    }

    /**
     * @param {string} email
     * @return {boolean}
     */
    static validateKind(email) {
        email = this.prepareEmail(email);

        const regex = this.getRegex();

        return regex.test(email);
    }

    /**
     * @return {RegExp}
     * @private
     */
    static getRegex() {
        return /^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    }

    /**
     * @param {string} email
     * @return {string}
     * @private
     */
    static prepareEmail(email) {
        return String(email).toLowerCase();
    }
}
</code></pre>

<p>To validate an email you can follow these ways:</p>

<pre><code>// First way.

try {
    EmailValidator.validate('balovbohdan@gmail.com');
} catch (e) {
    console.error(e.message);
}
</code></pre>

<pre><code>// Second way.

const email = 'balovbohdan@gmail.com';
const isValid = EmailValidator.validateKind(email);

if (isValid)
    console.log(`Email is valid: ${email}.`);
else
    console.log(`Email is invalid: ${email}.`);
</code></pre>


blocks|key|1559742|text|我正在使用这个函数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1559743|/**
+*+@param+{*}+email
+*/
export+const+validateEmail+=+email+=>+{
++++return+new+RegExp(/[\w-]%2B@([\w-]%2B\.)%2B[\w-]%2B/gm).test(email);
};|code-block|syntax|javascript|1559744|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>I am using this function </p>

<pre><code>/**
 * @param {*} email
 */
export const validateEmail = email =&gt; {
    return new RegExp(/[\w-]+@([\w-]+\.)+[\w-]+/gm).test(email);
};
</code></pre>


blocks|key|1775021|text|通用电子邮件正则表达式(RFC5322官方标准)：https://emailregex.com/|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1775022|JavaScript：|1775023|/%5E(([%5E<>()\[\]\\.,;:\s@"]%2B(\.[%5E<>()\[\]\\.,;:\s@"]%2B)*)%7C(".%2B"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])%7C(([a-zA-Z\-0-9]%2B\.)%2B[a-zA-Z]{2,}))$/|code-block|syntax|javascript|1775024|entityMap|0|LINK|mutability|MUTABLE|url|https://emailregex.com/^0|P|N|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

<p>General email regex (RFC 5322 Official Standard): <a href="https://emailregex.com/" rel="nofollow noreferrer">https://emailregex.com/</a></p>

<p>JavaScript:</p>

<pre><code>/^(([^&lt;&gt;()\[\]\\.,;:\s@"]+(\.[^&lt;&gt;()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/
</code></pre>


blocks|key|1559845|text|在输入字段中搜索@符号。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1559846|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

<p>Search for the @ sign in the input field. </p>


blocks|key|1560000|text|我添加了Regex+-我为我解决了更多的小问题，比如来自其他语言的字符或大写字母|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560001|%5E[a-zA-Z0-9][a-zA-Z0-9-_\.]%2B@([a-zA-Z]%7C[a-zA-Z0-9]?[a-zA-Z0-9-]%2B[a-zA-Z0-9])\.[a-zA-Z0-9]{2,10}(?:\.[a-zA-Z]{2,10})?$|code-block|syntax|javascript|1560002|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>I add my Regex - i solved for me more little issues like characters from other languages or capital letters </p>

<pre><code>^[a-zA-Z0-9][a-zA-Z0-9-_\.]+@([a-zA-Z]|[a-zA-Z0-9]?[a-zA-Z0-9-]+[a-zA-Z0-9])\.[a-zA-Z0-9]{2,10}(?:\.[a-zA-Z]{2,10})?$
</code></pre>


blocks|key|1775303|text|使用浏览器/运行时来解析输入，方法是预先附加一个协议并将其传递给URL应用程序接口，捕获任何错误并检查结果的username和hostname属性。它将处理基本上所有的转换和可能性(字符集的punycode，等等)。这只能确定输入是可解析的，而不是有效的--这只能通过检查目标计算机是否接收到该别名的消息来实现。不过，这提供了一个近似的(imo合理的)猜测，如果您愿意维护它并冒着无效拒绝的风险，则可以扩展到更具体、更现实。(请注意，它不会尝试寻址IPv4或IPv6地址，而只是使用域的广泛的面向客户的场景。)|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1775304|function+validEmail(email=''){
++++var+$0,+url,+isValid+=+false,+emailPatternInput+=+/%5E[%5E@]{1,64}@[%5E@]{4,253}$/,+emailPatternUrl+=+/%5E[%5E@]{1,64}@[a-z][a-z0-9\.-]{3,252}$/i;
++++email+=+email.trim();
++++try{
++++++++url+=+new+URL('http://'%2Bemail);
++++++++$0+=+`${url.username}@${url.hostname}`;
++++++++isValid+=+emailPatternInput.test(+email+);
++++++++if(!isValid)+throw+'invalid+email+pattern+on+input:'+%2B+email;
++++++++isValid+=+emailPatternUrl.test(+$0+);
++++++++if(!isValid)+throw+'invalid+email+pattern+on+url:'+%2B+$0;
++++++++console.log(`email+looks+legit+"${email}"+checking+url-parts:+"${$0+===+email+?+'-SAME-':$0}"`);
++++}catch(err){
++++++++console.error(`probably+not+an+email+address:+"${email}"`,+err);
++++};
++++return+isValid;
}

['user%2Bthis@はじめよう.みんな',+'stuff@things',+'user%2Bthat@host.com',+'Jean%2BFrançois@anydomain.museum','هيا@יאללה',+'试@例子.测试.مثال.آزمایشی',+'not@@really',+'no'].forEach(email=>console.log(validEmail(email),+email));|code-block|syntax|javascript|1775305|这是我能想到的最简单也是最普遍的例子。请在可以使其更准确的情况下对其进行编辑，同时保持其简单性和合理的、普遍允许的有效性。|1775306|另请参阅URL+API的MDN+URL文档URL、window.URL和Nodejs。|1775307|entityMap|0|LINK|mutability|MUTABLE|url|https://en.wikipedia.org/wiki/Punycode|1|https://nodejs.org/api/url.html|2|https://developer.mozilla.org/en-US/docs/Web/API/URL/URL|3|https://developer.mozilla.org/en-US/docs/Web/API/URL^0|W|3|1I|8|1R|8|2N|8|0|0|0|0|4|3|1|L|3|2|P|A|3|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@$9|19|A|1A|1|1B]]|E|$]]|$1|F|3|G|5|H|7|1C|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1D|8|@]|D|@]|E|$]]|$1|M|3|N|5|6|7|1E|8|@]|D|@$9|1F|A|1G|1|1H]|$9|1I|A|1J|1|1K]|$9|1L|A|1M|1|1N]]|E|$]]|$1|O|3|-4|5|6|7|1O|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]|W|$5|R|S|T|E|$U|X]]|Y|$5|R|S|T|E|$U|Z]]|10|$5|R|S|T|E|$U|11]]]]

<p>Use the browser/runtime to handle parsing the input by prepending a protocol and pass it to the <code>URL</code> API, trapping any errors and check the resulting <code>username</code> and <code>hostname</code> properties of the result. It will handle basically all transformations and possibilities (<a href="https://en.wikipedia.org/wiki/Punycode" rel="nofollow noreferrer">punycode</a> of character sets, etc). This only establishes that the input is parsable, not that is valid--that is only possible through checking if the destination machine receives messages for that alias. This provides a close (imo reasonable) guess though, and can be expanded to be more specific and realistic if you're comfortable both maintaining it and also risking invalid rejections. (Note it doesn't attempt to address IPv4 or IPv6 addresses, simply the broad range of customer-facing scenarios using a domain.)</p>

<pre><code>function validEmail(email=''){
    var $0, url, isValid = false, emailPatternInput = /^[^@]{1,64}@[^@]{4,253}$/, emailPatternUrl = /^[^@]{1,64}@[a-z][a-z0-9\.-]{3,252}$/i;
    email = email.trim();
    try{
        url = new URL('http://'+email);
        $0 = `${url.username}@${url.hostname}`;
        isValid = emailPatternInput.test( email );
        if(!isValid) throw 'invalid email pattern on input:' + email;
        isValid = emailPatternUrl.test( $0 );
        if(!isValid) throw 'invalid email pattern on url:' + $0;
        console.log(`email looks legit "${email}" checking url-parts: "${$0 === email ? '-SAME-':$0}"`);
    }catch(err){
        console.error(`probably not an email address: "${email}"`, err);
    };
    return isValid;
}

['user+this@はじめよう.みんな', 'stuff@things', 'user+that@host.com', 'Jean+François@anydomain.museum','هيا@יאללה', '试@例子.测试.مثال.آزمایشی', 'not@@really', 'no'].forEach(email=&gt;console.log(validEmail(email), email));
</code></pre>

<p>This is the both the simplest and most generally permissive example I can come up with. Please edit it in cases where it can be made to be more accurate while maintain its simplicity and reasonable generally permissive validity.</p>

<p>Also see MDN URL docs <a href="https://developer.mozilla.org/en-US/docs/Web/API/URL/URL" rel="nofollow noreferrer">URL</a>, <a href="https://developer.mozilla.org/en-US/docs/Web/API/URL" rel="nofollow noreferrer">window.URL</a> and Nodejs for <a href="https://nodejs.org/api/url.html" rel="nofollow noreferrer">URL</a> APIs.</p>


blocks|key|1560151|text|对于电子邮件验证，您可以创建自定义函数并使用正则表达式语法验证电子邮件：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560152|function+validateEmail(email){
++++++++var+reg+=+/%5E([A-Za-z0-9_\-\.])%2B\@([A-Za-z0-9_\-\.])%2B\.([A-Za-z]{2,4})$/;

+++++++//your+custom+code+here+to+check+your+email+address+

}|code-block|syntax|javascript|1560153|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>for email validation you can create your custom function and use regex syntax for validate email:</p>

<pre><code>function validateEmail(email){
        var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;

       //your custom code here to check your email address 

}
</code></pre>


blocks|key|1560187|text|你可以试试RegExp|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1560188|​|1560189|function+isValidEmail(+value+)+{
	return+/%5E[\w\-\.\%2B]%2B\@[a-zA-Z0-9\.\-]%2B\.[a-zA-z0-9]{2,5}$/.test(+value+);
}

console.log(+isValidEmail("mymail@mydomain.com")+)|code-block|syntax|javascript|1560190|1560191|entityMap^0|5|6|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|T|8|@]|D|@]|E|$K|L]]|$1|M|3|G|5|6|7|U|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|O|$]]

<p>You may try <code>RegExp</code></p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function isValidEmail( value ) {
	return /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,5}$/.test( value );
}

console.log( isValidEmail("mymail@mydomain.com") )</code></pre>
</div>
</div>
</p>


blocks|key|1775448|text|在我的例子中，我想避免使用~和#，这就是我使用another+solution的原因|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1775449|function+validEmail(email){
++const+regex+=+/%5E((?!\.)[\w\-_.]*[%5E.])(@\w%2B)(\.\w%2B(\.\w%2B)?[%5E.\W])$/;
++return+regex.test(email);
}|code-block|syntax|javascript|1775450|​|1775451|function+validEmail(email){
++const+regex+=+/%5E((?!\.)[\w\-_.]*[%5E.])(@\w%2B)(\.\w%2B(\.\w%2B)?[%5E.\W])$/;
++return+regex.test(email);
}

const+emails+=+[
'pio_pio@factory.com',
'~pio_pio@factory.com',
'pio_~pio@factory.com',
'pio_#pio@factory.com',
'pio_pio@#factory.com',
'pio_pio@factory.c#om',
'pio_pio@factory.c*om',
'pio%5E_pio@factory.com'
]

for(const+email+of+emails){
++document.write(email%2B'+:+'%2BvalidEmail(email)%2B'</br>');
}|1775452|1775453|entityMap|0|LINK|mutability|MUTABLE|url|https://regex101.com/r/SOgUIV/1^0|D|1|F|1|N|G|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@$9|12|A|13|1|14]]|E|$]]|$1|F|3|G|5|H|7|15|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|16|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|O|3|L|5|6|7|18|8|@]|D|@]|E|$]]|$1|P|3|-4|5|6|7|19|8|@]|D|@]|E|$]]]|Q|$R|$5|S|T|U|E|$V|W]]]]

<p>In my case, I wanted to avoid <code>~</code> and <code>#</code> that's why I have used <a href="https://regex101.com/r/SOgUIV/1" rel="nofollow noreferrer">another solution</a>:</p>
<pre><code>function validEmail(email){
  const regex = /^((?!\.)[\w\-_.]*[^.])(@\w+)(\.\w+(\.\w+)?[^.\W])$/;
  return regex.test(email);
}
</code></pre>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function validEmail(email){
  const regex = /^((?!\.)[\w\-_.]*[^.])(@\w+)(\.\w+(\.\w+)?[^.\W])$/;
  return regex.test(email);
}

const emails = [
'pio_pio@factory.com',
'~pio_pio@factory.com',
'pio_~pio@factory.com',
'pio_#pio@factory.com',
'pio_pio@#factory.com',
'pio_pio@factory.c#om',
'pio_pio@factory.c*om',
'pio^_pio@factory.com'
]

for(const email of emails){
  document.write(email+' : '+validEmail(email)+'&lt;/br&gt;');
}</code></pre>
</div>
</div>
</p>


blocks|key|1775487|text|您可以使用这个正则表达式(来自w3resource+(*not+related+to+W3C))：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1775488|/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/.test(emailValue)|code-block|syntax|javascript|1775489|如果你使用Node，你可以在后端和前端使用它。|1775490|我不知道其他后端语言，所以我不能评估其他用例。|1775491|entityMap|0|LINK|mutability|MUTABLE|url|https://www.w3resource.com/javascript/form/email-validation.php^0|F|W|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|C|$]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|C|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

<p>You can use this regex (from <a href="https://www.w3resource.com/javascript/form/email-validation.php" rel="nofollow noreferrer">w3resource (*not related to W3C)</a>):</p>
<pre><code>/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(emailValue)
</code></pre>
<p>If you use Node you can use this in the back-end as well as the front-end.</p>
<p>I don't know other back-end languages so I cannot evaluate for other use cases.</p>


blocks|key|1560331|text|哇，有很多答案包含略有不同的正则表达式。我已经尝试了很多次，我得到了不同的结果和各种不同的问题。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560332|对于UI验证，我擅长对looking+for+an+@+sign进行最基本的检查。值得注意的是，我总是使用标准的“验证电子邮件”进行服务器端验证，其中包含一个唯一的链接，供用户确认其电子邮件地址。|offset|length|1560333|if+(email.indexOf('@')+>+0)|code-block|syntax|javascript|1560334|我特意选择了0，即使从零开始也是如此，因为这也确保了@之前只有一个字符。|1560335|entityMap|0|LINK|mutability|MUTABLE|url|https://www.endyourif.com/validate-an-email-address-in-javascript/^0|0|B|L|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@$D|W|E|X|1|Y]]|A|$]]|$1|F|3|G|5|H|7|Z|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

<p>Wow, there are a lot of answers that contain slightly different regular expressions. I've tried many that I've got different results and a variety of different issues with all of them.</p>
<p>For UI validation, I'm good with the most basic check of <a href="https://www.endyourif.com/validate-an-email-address-in-javascript/" rel="nofollow noreferrer">looking for an @ sign</a>. It's important to note, that I always do server-side validation with a standard &quot;validate email&quot; that contains a unique link for the user to confirm their email address.</p>
<pre><code>if (email.indexOf('@') &gt; 0)
</code></pre>
<p>I have purposely chosen 0 even with zero-based as it also ensures there is a single character before the @.</p>


blocks|key|1775583|text|如果你得到这个错误:使用正则表达式是安全敏感的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1775584|那么这就是你要找的东西。此解决方案不受“正则表达式拒绝服务(ReDoS)”的影响|1775585|在不使用ReDoS的情况下验证电子邮件的正则表达式：|1775586|/%5E[a-z0-9](?!.*?[%5E\na-z0-9]{2})[%5E\s@]%2B@[%5E\s@]%2B\.[%5E\s@]%2B[a-z0-9]$/|code-block|syntax|javascript|1775587|请让我知道这个解决方案是否适用于您。谢谢。|1775588|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|Q|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|R|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

<p>If you get this error: Using regular expressions is security-sensitive.</p>
<p>Then here is what you are looking for. This solution is free from &quot; Regular expression Denial of Service (ReDoS) &quot;</p>
<p>Regex to validate emails without (ReDoS):</p>
<pre><code>/^[a-z0-9](?!.*?[^\na-z0-9]{2})[^\s@]+@[^\s@]+\.[^\s@]+[a-z0-9]$/
</code></pre>
<p>Please let me know if this solution works for you.
Thanks.</p>


blocks|key|1560469|text|这里的大多数答案都不是林特友好的，它是一团糟！它们中的一些也过时了！在花了很多时间之后，我决定使用一个名为email-validator的外部库，例如通过npm轻松安装它，并在您自己的项目中导入/需要它：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1560470|https://www.npmjs.com/package/email-validator|1560471|//NodeJs
const+validator+=+require("email-validator");
validator.validate("test@email.com");+//+true

//TypeScript/JavaScript
import+*+as+EmailValidator+from+'email-validator';
EmailValidator.validate("test@email.com");+//+true|code-block|syntax|javascript|1560472|entityMap|0|LINK|mutability|MUTABLE|url^0|1H|F|0|0|19|0|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|W|8|@]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|H|3|I|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|G]]]]

<p>Most of the answers here are not linter friendly, it's a mess! Some of them are also outdated!
After a lot of time spending, I decided to use an external library named <code>email-validator</code>, install it easily by npm for example and import/require it in your own project:</p>
<p><a href="https://www.npmjs.com/package/email-validator" rel="nofollow noreferrer">https://www.npmjs.com/package/email-validator</a></p>
<pre><code>//NodeJs
const validator = require(&quot;email-validator&quot;);
validator.validate(&quot;test@email.com&quot;); // true

//TypeScript/JavaScript
import * as EmailValidator from 'email-validator';
EmailValidator.validate(&quot;test@email.com&quot;); // true
</code></pre>


blocks|key|1560480|text|+++++//+Html+form+call+function+name+at+submit+button

++++<form+name="form1"+action="#">+
++++<input+type='text'+name='text1'/>
++++<input+type="submit"+name="submit"+value="Submit"+
++++onclick="ValidateEmail(document.form1.text1)"/>
+++</from>

++++//+Write+the+function+name+ValidateEmail+below

++++<script>
+++++function+ValidateEmail(inputText)
++++{
++var+mailformat+=+/%5E[a-zA-Z0-9.!#$%25&'*%2B/=?%5E_`{%7C}~-]%2B@[a-zA-Z0-9-]%2B(?:\.[a-zA-Z0-9-]%2B)*$/;
++++if(inputText.value.match(mailformat))
++++{
++++alert("Valid+email+address!");
++++document.form1.text1.focus();
++++return+true;
++++}
++++else
+++{
++++alert("You+have+entered+an+invalid+email+address!");
++++document.form1.text1.focus();
++++return+false;
++++}
++++}
+++</script>|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1560481|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>     // Html form call function name at submit button

    &lt;form name=&quot;form1&quot; action=&quot;#&quot;&gt; 
    &lt;input type='text' name='text1'/&gt;
    &lt;input type=&quot;submit&quot; name=&quot;submit&quot; value=&quot;Submit&quot; 
    onclick=&quot;ValidateEmail(document.form1.text1)&quot;/&gt;
   &lt;/from&gt;

    // Write the function name ValidateEmail below

    &lt;script&gt;
     function ValidateEmail(inputText)
    {
  var mailformat = /^[a-zA-Z0-9.!#$%&amp;'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/;
    if(inputText.value.match(mailformat))
    {
    alert(&quot;Valid email address!&quot;);
    document.form1.text1.focus();
    return true;
    }
    else
   {
    alert(&quot;You have entered an invalid email address!&quot;);
    document.form1.text1.focus();
    return false;
    }
    }
   &lt;/script&gt;
</code></pre>


blocks|key|1775707|text|电子邮件验证的另一个完美的正则表达式|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1775708|/%5E([%5E\s\@])%2B\@(([%5E\s\@\.])%2B\.)%2B([%5E\s\.]{2,})%2B$/|code-block|syntax|javascript|1775709|你可以在这里测试一下https://regex101.com/r/FV3pUI/2|offset|length|1775710|entityMap|0|LINK|mutability|MUTABLE|url|https://regex101.com/r/FV3pUI/2^0|0|0|A|V|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

<p>Yet another perfect regexp for email validation</p>
<pre class="lang-js prettyprint-override"><code>/^([^\s\@])+\@(([^\s\@\.])+\.)+([^\s\.]{2,})+$/
</code></pre>
<p>You can test it here <a href="https://regex101.com/r/FV3pUI/2" rel="nofollow noreferrer">https://regex101.com/r/FV3pUI/2</a></p>


blocks|key|1775774|text|这对于一个简单的电子邮件正则表达式非常有效：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1775775|anythingExceptAtOrSpace@anythingExceptAtOrSpace.anythingExceptAtOrSpace|1775776|/%5E[%5E@+]%2B@[%5E@+]%2B\.[%5E@+]%2B$/|code-block|syntax|javascript|1775777|要测试：|1775778|​|1775779|const+emailRegex+=+/%5E[%5E@+]%2B@[%5E@+]%2B\.[%5E@+]%2B$/
const+result1+=+emailRegex.test('hello@there.com')
console.log(result1)+//+true
const+result2+=+emailRegex.test('hel@lo@there.com')
console.log(result2)+//+false|1775780|1775781|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|T|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|U|8|@]|9|@]|A|$]]|$1|K|3|L|5|6|7|V|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|O|3|L|5|6|7|X|8|@]|9|@]|A|$]]|$1|P|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|Q|$]]

<p>This works well for a simple email regex:</p>
<p>anythingExceptAtOrSpace@anythingExceptAtOrSpace.anythingExceptAtOrSpace</p>
<pre><code>/^[^@ ]+@[^@ ]+\.[^@ ]+$/
</code></pre>
<p>To test:</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>const emailRegex = /^[^@ ]+@[^@ ]+\.[^@ ]+$/
const result1 = emailRegex.test('hello@there.com')
console.log(result1) // true
const result2 = emailRegex.test('hel@lo@there.com')
console.log(result2) // false</code></pre>
</div>
</div>
</p>


blocks|key|1560624|text|//+Try+this+regular+Expression+by+ES6+function

const+emailValidate+=+(email)+=>+{
++const+regexp=+/%5E[\w.%25%2B-]%2B@[\w.-]%2B\.[\w]{2,6}$/;
++return+regexp.test(email);
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1560625|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>// Try this regular Expression by ES6 function

const emailValidate = (email) =&gt; {
  const regexp= /^[\w.%+-]+@[\w.-]+\.[\w]{2,6}$/;
  return regexp.test(email);
}
</code></pre>


blocks|key|1775814|text|简单的建议，因为我已经从答案中看到了困惑。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1775815|function+validaEmail(email){

++if(email.includes("@")){

++++if(email.split("@")[1].includes(".")){
++++++return+true;
++++}

++}

++return+false;
++
}|code-block|syntax|javascript|1775816|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Simple suggestion, since i've seen confusion through the answers.</p>
<pre><code>function validaEmail(email){

  if(email.includes(&quot;@&quot;)){

    if(email.split(&quot;@&quot;)[1].includes(&quot;.&quot;)){
      return true;
    }

  }

  return false;
  
}
</code></pre>


blocks|key|1560721|text|找到了完美的正则表达式。它不包括double+@，two“。在一行中，英语以外的语言和行首的额外字符(".“、"-”、"!“等)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560722|const+regexp+=+/%5E\w%2B([\.-]?\w%2B)*@\w%2B([\.-]?\w%2B)*(\.\w{2,3})%2B$/;
if+(!this.value.match(regexp))+{
//+on+error,+we+get+into+the+condition
++++this.classList.add('error');
}
//+this+-+email+input|code-block|syntax|javascript|1560723|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Found the perfect regular expression.
It excludes double @, two &quot;.&quot; in a row, languages other than English and extra characters at the beginning of the line (&quot;.&quot;, &quot;-&quot;, &quot;!&quot;, etc.)</p>
<pre><code>const regexp = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;
if (!this.value.match(regexp)) {
// on error, we get into the condition
    this.classList.add('error');
}
// this - email input
</code></pre>


<p>What's the best way to validate an email address in JavaScript with a regular expression?</p>


What's the best way to validate an email address in JavaScript?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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用正则表达式在JavaScript中验证电子邮件地址的最佳方法是什么？

问在JavaScript中验证电子邮件地址的最佳方法是什么？
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