blocks|key|3004128|text|而不是|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3004129|{1-3}|code-block|syntax|javascript|3004130|你应该把|3004131|{1,3}|3004132|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

And instead of

<pre><code>{1-3}
</code></pre>

you should put

<pre><code>{1,3}
</code></pre>

blocks|key|3004146|text|您得到的正则表达式已经存在几个问题：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3004147|首先，它包含点。在regex中，点的意思是“匹配任何字符”，您只需要匹配一个实际的点。为此，您需要对其进行转义，因此在点前加一个反斜杠。|3004148|其次，但您可以在每个部分中匹配任意三位数字。这意味着您将匹配0到999之间的任何数字，这显然包含许多无效的IP地址号码。|3004149|这可以通过使数字匹配更复杂来解决；这个网站上有其他答案解释了如何做到这一点，但坦率地说，这不值得努力--在我看来，你最好用点来分割字符串，然后只验证这四个块是否为数字整数范围--即：|3004150|if(block+>=+0+&&+block+<=+255)+{....}|code-block|syntax|javascript|3004151|希望这能有所帮助。|3004152|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|S|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|I|5|J|7|U|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

The regex you've got already has several problems:

Firstly, it contains dots. In regex, a dot means "match any character", where you need to match just an actual dot. For this, you need to escape it, so put a back-slash in front of the dots.

Secondly, but you're matching any three digits in each section. This means you'll match any number between 0 and 999, which obviously contains a lot of invalid IP address numbers.

This can be solved by making the number matching more complex; there are other answers on this site which explain how to do that, but frankly it's not worth the effort -- in my opinion, you'd be much better off splitting the string by the dots, and then just validating the four blocks as numeric integer ranges -- ie:

<pre><code>if(block &gt;= 0 &amp;&amp; block &lt;= 255) {....}
</code></pre>

Hope that helps.

blocks|key|290880|text|试试这个吧..来源：here。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|290881|"\b(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\b"|code-block|syntax|javascript|290882|entityMap|0|LINK|mutability|MUTABLE|url|http://www.geekzilla.co.uk/view0CBFD9A7-621D-4B0C-9554-91FD48AADC77.htm^0|A|4|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]]]]

Try this one.. Source from <a href="http://www.geekzilla.co.uk/view0CBFD9A7-621D-4B0C-9554-91FD48AADC77.htm" rel="noreferrer">here</a>.

<pre><code>"\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b"
</code></pre>

blocks|key|3217672|text|\b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3217673|如果您知道seachdata不包含无效的IP地址，则匹配0.0.0.0到999.999.999.999|unstyled|3217674|\b(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\b|3217675|用于精确匹配IP号码-4个号码中的每一个都存储在自己的捕获组中，因此您可以在以后访问它们|3217676|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>\b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b
</code></pre>

matches 0.0.0.0 through 999.999.999.999
use if you know the seachdata does not contain invalid IP addresses

<pre><code>\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b
</code></pre>

use to match IP numbers with accurracy - each of the 4 numbers is stored into it's own capturing group, so you can access them later

blocks|key|288420|text|IP地址格式的正则表达式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|288421|/%5E(\d\d?)%7C(1\d\d)%7C(0\d\d)%7C(2[0-4]\d)%7C(2[0-5])\.(\d\d?)%7C(1\d\d)%7C(0\d\d)%7C(2[0-4]\d)%7C(2[0-5])\.(\d\d?)%7C(1\d\d)%7C(0\d\d)%7C(2[0-4]\d)%7C(2[0-5])$/;|code-block|syntax|javascript|288422|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|$]]

Regular expression for the IP address format:

<pre><code>/^(\d\d?)|(1\d\d)|(0\d\d)|(2[0-4]\d)|(2[0-5])\.(\d\d?)|(1\d\d)|(0\d\d)|(2[0-4]\d)|(2[0-5])\.(\d\d?)|(1\d\d)|(0\d\d)|(2[0-4]\d)|(2[0-5])$/;
</code></pre>

blocks|key|285416|text|也许这样更好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|285417|function+checkIP(ip)+{
++++var+x+=+ip.split("."),+x1,+x2,+x3,+x4;

++++if+(x.length+==+4)+{
++++++++x1+=+parseInt(x[0],+10);
++++++++x2+=+parseInt(x[1],+10);
++++++++x3+=+parseInt(x[2],+10);
++++++++x4+=+parseInt(x[3],+10);

++++++++if+(isNaN(x1)+%7C%7C+isNaN(x2)+%7C%7C+isNaN(x3)+%7C%7C+isNaN(x4))+{
++++++++++++return+false;
++++++++}

++++++++if+((x1+>=+0+&&+x1+<=+255)+&&+(x2+>=+0+&&+x2+<=+255)+&&+(x3+>=+0+&&+x3+<=+255)+&&+(x4+>=+0+&&+x4+<=+255))+{
++++++++++++return+true;
++++++++}
++++}
++++return+false;
}++++|code-block|syntax|javascript|285418|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|$]]

it is maybe better:

<pre><code>function checkIP(ip) {
 var x = ip.split("."), x1, x2, x3, x4;

 if (x.length == 4) {
 x1 = parseInt(x[0], 10);
 x2 = parseInt(x[1], 10);
 x3 = parseInt(x[2], 10);
 x4 = parseInt(x[3], 10);

 if (isNaN(x1) || isNaN(x2) || isNaN(x3) || isNaN(x4)) {
 return false;
 }

 if ((x1 &gt;= 0 &amp;&amp; x1 &lt;= 255) &amp;&amp; (x2 &gt;= 0 &amp;&amp; x2 &lt;= 255) &amp;&amp; (x3 &gt;= 0 &amp;&amp; x3 &lt;= 255) &amp;&amp; (x4 &gt;= 0 &amp;&amp; x4 &lt;= 255)) {
 return true;
 }
 }
 return false;
} 
</code></pre>

blocks|key|285426|text|如果您想在现代浏览器中使用比ipv4的正则表达式更好的可读性，可以使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|285427|function+checkIsIPV4(entry)+{
++var+blocks+=+entry.split(".");
++if(blocks.length+===+4)+{
++++return+blocks.every(function(block)+{
++++++return+parseInt(block,10)+>=0+&&+parseInt(block,10)+<=+255;
++++});
++}
++return+false;
}|code-block|syntax|javascript|285428|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|$]]

If you want something more readable than regex for ipv4 in modern browsers you can go with

<pre><code>function checkIsIPV4(entry) {
 var blocks = entry.split(".");
 if(blocks.length === 4) {
 return blocks.every(function(block) {
 return parseInt(block,10) &gt;=0 &amp;&amp; parseInt(block,10) &lt;= 255;
 });
 }
 return false;
}
</code></pre>

blocks|key|285434|text|试试这个，它是一个更短的版本：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|285435|%5E(?!0)(?!.*\.$)((1?\d?\d%7C25[0-5]%7C2[0-4]\d)(\.%7C$)){4}$|code-block|syntax|javascript|285436|解释：|285437|%5E+start+of+string
++(?!0)+++++++++Assume+IP+cannot+start+with+0
++(?!.*\.$)+++++Make+sure+string+does+not+end+with+a+dot
++(
++++(
++++1?\d?\d%7C+++A+single+digit,+two+digits,+or+100-199
++++25[0-5]%7C+++The+numbers+250-255
++++2[0-4]\d+++The+numbers+200-249
++++)
++\.%7C$+the+number+must+be+followed+by+either+a+dot+or+end-of-string+-+to+match+the+last+number
++){4}+++++++++Expect+exactly+four+of+these
$+end+of+string|285438|浏览器控制台的单元测试：|285439|var+rx=/%5E(?!0)(?!.*\.$)((1?\d?\d%7C25[0-5]%7C2[0-4]\d)(\.%7C$)){4}$/;
var+valid=['1.2.3.4','11.11.11.11','123.123.123.123','255.250.249.0','1.12.123.255','127.0.0.1','1.0.0.0'];
var+invalid=['0.1.1.1','01.1.1.1','012.1.1.1','1.2.3.4.','1.2.3\n4','1.2.3.4\n','259.0.0.1','123.','1.2.3.4.5','.1.2.3.4','1,2,3,4','1.2.333.4','1.299.3.4'];
valid.forEach(function(s){if+(!rx.test(s))console.log('bad+valid:+'%2Bs);});
invalid.forEach(function(s){if+(rx.test(s))+console.log('bad+invalid:+'%2Bs);});|285440|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]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Try this one, it's a shorter version:

<pre><code>^(?!0)(?!.*\.$)((1?\d?\d|25[0-5]|2[0-4]\d)(\.|$)){4}$
</code></pre>

Explained: 

<pre><code>^ start of string
 (?!0) Assume IP cannot start with 0
 (?!.*\.$) Make sure string does not end with a dot
 (
 (
 1?\d?\d| A single digit, two digits, or 100-199
 25[0-5]| The numbers 250-255
 2[0-4]\d The numbers 200-249
 )
 \.|$ the number must be followed by either a dot or end-of-string - to match the last number
 ){4} Expect exactly four of these
$ end of string
</code></pre>

Unit test for a browser's console:

<pre><code>var rx=/^(?!0)(?!.*\.$)((1?\d?\d|25[0-5]|2[0-4]\d)(\.|$)){4}$/;
var valid=['1.2.3.4','11.11.11.11','123.123.123.123','255.250.249.0','1.12.123.255','127.0.0.1','1.0.0.0'];
var invalid=['0.1.1.1','01.1.1.1','012.1.1.1','1.2.3.4.','1.2.3\n4','1.2.3.4\n','259.0.0.1','123.','1.2.3.4.5','.1.2.3.4','1,2,3,4','1.2.333.4','1.299.3.4'];
valid.forEach(function(s){if (!rx.test(s))console.log('bad valid: '+s);});
invalid.forEach(function(s){if (rx.test(s)) console.log('bad invalid: '+s);});
</code></pre>

blocks|key|287607|text|可能会迟到，但有人可以试试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|287608|有效IP地址的示例|offset|length|style|BOLD|287609|115.42.150.37
192.168.0.1
110.234.52.124|code-block|syntax|javascript|287610|无效IP地址的示例|287611|210.110+–+must+have+4+octets
255+–+must+have+4+octets
y.y.y.y+–+only+digits+are+allowed
255.0.0.y+–+only+digits+are+allowed
666.10.10.20+–+octet+number+must+be+between+[0-255]
4444.11.11.11+–+octet+number+must+be+between+[0-255]
33.3333.33.3+–+octet+number+must+be+between+[0-255]|287612|用于验证IP地址的JavaScript代码|287613|function+ValidateIPaddress(ipaddress)+{++
++if+(/%5E(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)$/.test(ipaddress))+{++
++++return+(true)++
++}++
++alert("You+have+entered+an+invalid+IP+address!")++
++return+(false)++
}++|287614|entityMap^0|0|7|2|0|0|0|6|7|2|0|0|0|8|9|C|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|X|8|@$D|Y|E|Z|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|10|8|@]|9|@]|A|$K|L]]|$1|M|3|N|5|6|7|11|8|@$D|12|E|13|F|G]|$D|14|E|15|F|G]]|9|@]|A|$]]|$1|O|3|P|5|J|7|16|8|@]|9|@]|A|$K|L]]|$1|Q|3|R|5|6|7|17|8|@$D|18|E|19|F|G]|$D|1A|E|1B|F|G]]|9|@]|A|$]]|$1|S|3|T|5|J|7|1C|8|@]|9|@]|A|$K|L]]|$1|U|3|-4|5|6|7|1D|8|@]|9|@]|A|$]]]|V|$]]

May be late but, someone could try:

Example of VALID IP address

<pre><code>115.42.150.37
192.168.0.1
110.234.52.124
</code></pre>

Example of INVALID IP address

<pre><code>210.110 – must have 4 octets
255 – must have 4 octets
y.y.y.y – only digits are allowed
255.0.0.y – only digits are allowed
666.10.10.20 – octet number must be between [0-255]
4444.11.11.11 – octet number must be between [0-255]
33.3333.33.3 – octet number must be between [0-255]
</code></pre>

JavaScript code to validate an IP address

<pre><code>function ValidateIPaddress(ipaddress) { 
 if (/^(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(ipaddress)) { 
 return (true) 
 } 
 alert("You have entered an invalid IP address!") 
 return (false) 
} 
</code></pre>

blocks|key|288462|text|不要写你自己的正则表达式或复制粘贴！你可能不会涵盖所有的边缘‘t+(IPv6，但也包括八进制IP，等等)。使用is-ip+package+from+npm：|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|CODE|entityRanges|data|288463|var+isIp+=+require('is-ip');

isIp('192.168.0.1');

isIp('1:2:3:4:5:6:7:8');|code-block|syntax|javascript|288464|将返回一个布尔值。|288465|Downvoters：愿意解释一下为什么使用积极维护的库比从网站复制粘贴更好吗？|288466|entityMap|0|LINK|mutability|MUTABLE|url|https://www.npmjs.com/package/is-ip^0|0|I|1J|5|1J|M|0|0|0|0|0|A|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|D]]|E|@$9|12|A|13|1|14]]|F|$]]|$1|G|3|H|5|I|7|15|8|@]|E|@]|F|$J|K]]|$1|L|3|M|5|6|7|16|8|@]|E|@]|F|$]]|$1|N|3|O|5|6|7|17|8|@$9|18|A|19|B|C]]|E|@]|F|$]]|$1|P|3|-4|5|6|7|1A|8|@]|E|@]|F|$]]]|Q|$R|$5|S|T|U|F|$V|W]]]]

Don't write your own regex or copy paste! You probably won't cover all edge ceses (IPv6, but also octal IPs, etc). Use the <a href="https://www.npmjs.com/package/is-ip" rel="noreferrer"><code>is-ip</code> package from npm</a>: 

<pre><code>var isIp = require('is-ip');

isIp('192.168.0.1');

isIp('1:2:3:4:5:6:7:8');
</code></pre>

Will return a Boolean.

Downvoters: care to explain why using an actively maintained library is better than copy pasting from a website?

blocks|key|3217849|text|/%5E(?!.*\.$)((?!0\d)(1?\d?\d%7C25[0-5]%7C2[0-4]\d)(\.%7C$)){4}$/|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|3217850|全部归功于oriadam。我会在他/她的回答下面发表评论，建议我所做的双零改变，但我在这里还没有足够的声誉……|unstyled|offset|length|3217851|更改|style|BOLD|3217852|3217853|-(?!0)因为以零('0.248.42.223')开头的IPv4地址是有效的+IPv4，因为带有前导零('63.14.209.00‘和'011.012.013.014')的IPv4地址可以sometimes+be+interpreted+as+|unordered-list-item|3217854|3217855|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/26445549/5950725|1|https://superuser.com/a/857618/629196^0|0|5|7|0|0|0|2|0|0|10|3|2N|S|1|0|0^^$0|@$1|2|3|4|5|6|7|11|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|12|8|@]|9|@$G|13|H|14|1|15]]|A|$]]|$1|I|3|J|5|F|7|16|8|@$G|17|H|18|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|F|7|19|8|@]|9|@]|A|$]]|$1|N|3|O|5|P|7|1A|8|@$G|1B|H|1C|K|L]]|9|@$G|1D|H|1E|1|1F]]|A|$]]|$1|Q|3|-4|5|F|7|1G|8|@]|9|@]|A|$]]|$1|R|3|-4|5|F|7|1H|8|@]|9|@]|A|$]]]|S|$T|$5|U|V|W|A|$X|Y]]|Z|$5|U|V|W|A|$X|10]]]]

<pre><code>/^(?!.*\.$)((?!0\d)(1?\d?\d|25[0-5]|2[0-4]\d)(\.|$)){4}$/
</code></pre>

Full credit to <a href="https://stackoverflow.com/a/26445549/5950725">oriadam</a>. I would have commented below his/her answer to suggest the double zero change I made, but I do not have enough reputation here yet...

change:

<ul>
<li>-(?!0) Because IPv4 addresses starting with zeros ('0.248.42.223') are valid (<a href="https://learningnetwork.cisco.com/thread/7432#31148" rel="noreferrer">but not usable</a>)</li>
<li>+(?!0\d) Because IPv4 addresses with leading zeros ('63.14.209.00' and '011.012.013.014') can <a href="https://superuser.com/a/857618/629196">sometimes be interpreted as octal</a></li>
</ul>

blocks|key|290983|text|如果您使用的是nodejs，请尝试：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|290984|require('net').isIP('10.0.0.1')|offset|length|style|CODE|290985|文档|290986|entityMap^0|0|0|V|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

If you are using nodejs try:

<code>require('net').isIP('10.0.0.1')</code>

doc <a href="https://nodejs.org/api/net.html#net_net_isip_input" rel="noreferrer">net.isIP()</a>

blocks|key|290988|text|如果你写了正确的代码，你只需要这个非常简单的正则表达式:+/\d{1,3}/|type|unstyled|depth|inlineStyleRanges|entityRanges|data|290989|function+isIP(ip)+{
++++let+arrIp+=+ip.split(".");
++++if+(arrIp.length+!==+4)+return+"Invalid+IP";
++++let+re+=+/\d{1,3}/;
++++for+(let+oct+of+arrIp)+{
++++++++if+(oct.match(re)+===+null)+return+"Invalid+IP"
++++++++if+(Number(oct)+<+0+%7C%7C+Number(oct)+>+255)
++++++++++++return+"Invalid+IP";
}
++++return+"Valid+IP";
}|code-block|syntax|javascript|290990|但实际上，通过根本不使用任何正则表达式，您可以获得更简单的代码：|290991|function+isIp(ip)+{
++++var+arrIp+=+ip.split(".");
++++if+(arrIp.length+!==+4)+return+"Invalid+IP";
++++for+(let+oct+of+arrIp)+{
++++++++if+(+isNaN(oct)+%7C%7C+Number(oct)+<+0+%7C%7C+Number(oct)+>+255)
++++++++++++return+"Invalid+IP";
}
++++return+"Valid+IP";
}|290992|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you wrtie the proper code you need only this very simple regular expression: /\d{1,3}/

<pre><code>function isIP(ip) {
 let arrIp = ip.split(".");
 if (arrIp.length !== 4) return "Invalid IP";
 let re = /\d{1,3}/;
 for (let oct of arrIp) {
 if (oct.match(re) === null) return "Invalid IP"
 if (Number(oct) &lt; 0 || Number(oct) &gt; 255)
 return "Invalid IP";
}
 return "Valid IP";
}
</code></pre>

But actually you get even simpler code by not using any regular expression at all:

<pre><code>function isIp(ip) {
 var arrIp = ip.split(".");
 if (arrIp.length !== 4) return "Invalid IP";
 for (let oct of arrIp) {
 if ( isNaN(oct) || Number(oct) &lt; 0 || Number(oct) &gt; 255)
 return "Invalid IP";
}
 return "Valid IP";
}
</code></pre>

blocks|key|288529|text|总是寻找变化，似乎是一个重复的任务，所以使用forEach如何！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|288530|function+checkIP(ip)+{
++//assume+IP+is+valid+to+start,+once+false+is+found,+always+false
++var+test+=+true;

++//uses+forEach+method+to+test+each+block+of+IPv4+address
++ip.split('.').forEach(validateIP4);

++if+(!test)+
++++alert("Invalid+IP4+format\n"%2Bip)+
++else+
++++alert("IP4+format+correct\n"%2Bip);

++function+validateIP4(num,+index,+arr)+{
++++//returns+NaN+if+not+an+Int
++++item+=+parseInt(num,+10);
++++//test+validates+Int,+0-255+range+and+4+bytes+of+address
++++//+&&+test;+at+end+required+because+this+function+called+for+each+block
++++test+=+!isNaN(item)+&&+!isNaN(num)+&&+item+>=0+&&+item+<+256+&&+arr.length==4+&&+test;
++}
}|code-block|syntax|javascript|288531|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|$]]

Always looking for variations, seemed to be a repetitive task so how about using forEach! 

<pre><code>function checkIP(ip) {
 //assume IP is valid to start, once false is found, always false
 var test = true;

 //uses forEach method to test each block of IPv4 address
 ip.split('.').forEach(validateIP4);

 if (!test) 
 alert("Invalid IP4 format\n"+ip) 
 else 
 alert("IP4 format correct\n"+ip);

 function validateIP4(num, index, arr) {
 //returns NaN if not an Int
 item = parseInt(num, 10);
 //test validates Int, 0-255 range and 4 bytes of address
 // &amp;&amp; test; at end required because this function called for each block
 test = !isNaN(item) &amp;&amp; !isNaN(num) &amp;&amp; item &gt;=0 &amp;&amp; item &lt; 256 &amp;&amp; arr.length==4 &amp;&amp; test;
 }
}
</code></pre>

blocks|key|287648|text|在测试类型时不那么严格，而不是有效性。例如，在对列进行排序时，可以使用此检查来查看要使用哪种排序。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|287649|export+const+isIpAddress+=+(ipAddress)+=>+
++++/%5E((\d){1,3}\.){3}(\d){1,3}$/.test(ipAddress)|code-block|syntax|javascript|287650|在检查有效性时，请使用此测试。更严格的测试检查IP+8位数字是否在0-255范围内：|287651|export+const+isValidIpAddress+=+(ipAddress)+=>+
++++/%5E((25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)\.){3}(25[0-5]%7C2[0-4][0-9]%7C[01]?[0-9][0-9]?)$/.test(ipAddress)|287652|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

A less stringent when testing the type not the validity. For example when sorting columns use this check to see which sort to use.

<pre><code>export const isIpAddress = (ipAddress) =&gt; 
 /^((\d){1,3}\.){3}(\d){1,3}$/.test(ipAddress)
</code></pre>

When checking for validity use this test. An even more stringent test checking that the IP 8-bit numbers are in the range 0-255:

<pre><code>export const isValidIpAddress = (ipAddress) =&gt; 
 /^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/.test(ipAddress)
</code></pre>

blocks|key|3218167|text|再加上一篇迟到的文章：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3218168|%5E(?!\.)((%5E%7C\.)([1-9]?\d%7C1\d\d%7C2(5[0-5]%7C[0-4]\d))){4}$|code-block|syntax|javascript|3218169|在我检查的答案中，它们要么较长，要么在验证过程中不完整。在我的经验中，更长的时间意味着更难忽视，因此更容易出错。出于同样的原因，我喜欢避免重复类似的模式。|3218170|当然，主要的部分是对数字-0到255的测试，但也要确保它不允许初始零(除了当它是一个1的时候)：|3218171|[1-9]?\d%7C1\d\d%7C2(5[0-5]%7C[0-4]\d)|3218172|三个替换-一个用于sub100：[1-9]?\d，一个用于100-199：1\d\d，最后是200-255：2(5[0-5]%7C[0-4]\d)。|offset|length|style|CODE|3218173|在此之前，将测试行的开始或a点.，并通过附加的{4}对整个表达式进行4次测试。|BOLD|3218174|这个针对四个字节表示的完整测试从测试行的开始开始，然后进行否定的前视，以避免以.：%5E(?!\.)开头的地址，并以测试行的结束($)结束。|3218175|See+some+samples+here+at+regex101.|3218176|entityMap|0|LINK|mutability|MUTABLE|url|https://regex101.com/r/MQXQ5F/3^0|0|0|0|0|0|G|8|11|5|1I|H|0|C|1|F|1|N|3|0|13|1|15|7|1R|1|0|0|Y|0|0^^$0|@$1|2|3|4|5|6|7|17|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|18|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|19|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|1A|8|@]|9|@]|A|$]]|$1|K|3|L|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|M|3|N|5|6|7|1C|8|@$O|1D|P|1E|Q|R]|$O|1F|P|1G|Q|R]|$O|1H|P|1I|Q|R]]|9|@]|A|$]]|$1|S|3|T|5|6|7|1J|8|@$O|1K|P|1L|Q|U]|$O|1M|P|1N|Q|R]|$O|1O|P|1P|Q|R]]|9|@]|A|$]]|$1|V|3|W|5|6|7|1Q|8|@$O|1R|P|1S|Q|R]|$O|1T|P|1U|Q|R]|$O|1V|P|1W|Q|R]]|9|@]|A|$]]|$1|X|3|Y|5|6|7|1X|8|@]|9|@$O|1Y|P|1Z|1|20]]|A|$]]|$1|Z|3|-4|5|6|7|21|8|@]|9|@]|A|$]]]|10|$11|$5|12|13|14|A|$15|16]]]]

Throwing in a late contribution:

<pre><code>^(?!\.)((^|\.)([1-9]?\d|1\d\d|2(5[0-5]|[0-4]\d))){4}$
</code></pre>

Of the answers I checked, they're either longer or incomplete in their verification. Longer, in my experience, means harder to overlook and therefore more prone to be erroneous. And I like to avoid repeating similar patters, for the same reason.

The main part is, of course, the test for a number - 0 to 255, but also making sure it doesn't allow initial zeroes (except for when it's a single one):

<pre><code>[1-9]?\d|1\d\d|2(5[0-5]|[0-4]\d)
</code></pre>

Three alternations - one for sub 100: <code>[1-9]?\d</code>, one for 100-199: <code>1\d\d</code> and finally 200-255: <code>2(5[0-5]|[0-4]\d)</code>.

This is preceded by a test for start of line or a dot <code>.</code>, and this whole expression is tested for 4 times by the appended <code>{4}</code>.

This complete test for four byte representations is started by testing for start of line followed by a negative look ahead to avoid addresses starting with a <code>.</code>: <code>^(?!\.)</code>, and ended with a test for end of line (<code>$</code>).

<a href="https://regex101.com/r/MQXQ5F/3" rel="nofollow noreferrer">See some samples here at regex101.</a>

blocks|key|3218194|text|简短的RegEx：%5E(?:(?:%5E%7C\.)(?:2(?:5[0-5]%7C[0-4]\d)%7C1?\d?\d)){4}$|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3218195|示例|BOLD|3218196|​|3218197|const+isValidIp+=+value+=>+(/%5E(?:(?:%5E%7C\.)(?:2(?:5[0-5]%7C[0-4]\d)%7C1?\d?\d)){4}$/.test(value)+?+true+:+false);


//+valid
console.log("isValidIp('0.0.0.0')+?+",+isValidIp('0.0.0.0'));
console.log("isValidIp('115.42.150.37')+?+",+isValidIp('115.42.150.37'));
console.log("isValidIp('192.168.0.1')+?+",+isValidIp('192.168.0.1'));
console.log("isValidIp('110.234.52.124'+?+",+isValidIp('110.234.52.124'));
console.log("isValidIp('115.42.150.37')+?+",+isValidIp('115.42.150.37'));
console.log("isValidIp('115.42.150.38')+?+",+isValidIp('115.42.150.38'));
console.log("isValidIp('115.42.150.50')+?+",+isValidIp('115.42.150.50'));

//+Invalid
console.log("isValidIp('210.110')+?+",+isValidIp('210.110'));
console.log("isValidIp('255')+?+",+isValidIp('255'));
console.log("isValidIp('y.y.y.y'+?+",+isValidIp('y.y.y.y'));
console.log("+isValidIp('255.0.0.y')+?+",+isValidIp('255.0.0.y'));
console.log("isValidIp('666.10.10.20')+?+",+isValidIp('666.10.10.20'));
console.log("isValidIp('4444.11.11.11')+?+",+isValidIp('4444.11.11.11'));
console.log("isValidIp('33.3333.33.3')+?+",+isValidIp('33.3333.33.3'));|code-block|syntax|javascript|3218198|3218199|entityMap^0|9|1C|0|0|2|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@$9|W|A|X|B|H]]|D|@]|E|$]]|$1|I|3|J|5|6|7|Y|8|@]|D|@]|E|$]]|$1|K|3|L|5|M|7|Z|8|@]|D|@]|E|$N|O]]|$1|P|3|J|5|6|7|10|8|@]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|R|$]]

A short RegEx: <code>^(?:(?:^|\.)(?:2(?:5[0-5]|[0-4]\d)|1?\d?\d)){4}$</code>

Example

<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 isValidIp = value =&gt; (/^(?:(?:^|\.)(?:2(?:5[0-5]|[0-4]\d)|1?\d?\d)){4}$/.test(value) ? true : false);


// valid
console.log("isValidIp('0.0.0.0') ? ", isValidIp('0.0.0.0'));
console.log("isValidIp('115.42.150.37') ? ", isValidIp('115.42.150.37'));
console.log("isValidIp('192.168.0.1') ? ", isValidIp('192.168.0.1'));
console.log("isValidIp('110.234.52.124' ? ", isValidIp('110.234.52.124'));
console.log("isValidIp('115.42.150.37') ? ", isValidIp('115.42.150.37'));
console.log("isValidIp('115.42.150.38') ? ", isValidIp('115.42.150.38'));
console.log("isValidIp('115.42.150.50') ? ", isValidIp('115.42.150.50'));

// Invalid
console.log("isValidIp('210.110') ? ", isValidIp('210.110'));
console.log("isValidIp('255') ? ", isValidIp('255'));
console.log("isValidIp('y.y.y.y' ? ", isValidIp('y.y.y.y'));
console.log(" isValidIp('255.0.0.y') ? ", isValidIp('255.0.0.y'));
console.log("isValidIp('666.10.10.20') ? ", isValidIp('666.10.10.20'));
console.log("isValidIp('4444.11.11.11') ? ", isValidIp('4444.11.11.11'));
console.log("isValidIp('33.3333.33.3') ? ", isValidIp('33.3333.33.3'));</code></pre>
</div>
</div>

blocks|key|287800|text|下面的解决方案不接受填充零位|type|unstyled|depth|inlineStyleRanges|entityRanges|data|287801|以下是验证IP地址的最简单方法，让我们将其分解：|287802|事实：一个有效的IP地址是有4+octets的，每个八位字节可以是0+-+255之间的一个数字|offset|length|style|BOLD|CODE|287803|匹配0+-+255之间的任意值的正则表达式细分|287804|287805|25[0-5]匹配250+-+255|unordered-list-item|287806|2[0-4][0-9]匹配200+-+249|287807|1[0-9][0-9]匹配100+-+199|287808|[1-9][0-9]?匹配1+-+99|287809|0匹配0|287810|287811|const+octet+=+'(25[0-5]%7C2[0-4][0-9]%7C1[0-9][0-9]%7C[1-9][0-9]?%7C0)';|code-block|syntax|javascript|287812|注意事项：当使用new+RegExp时，你应该使用\\.而不是\.，因为字符串会被转义两次。|287813|function+isValidIP(str)+{
++const+octet+=+'(25[0-5]%7C2[0-4][0-9]%7C1[0-9][0-9]%7C[1-9][0-9]?%7C0)';
++const+regex+=+new+RegExp(`%5E${octet}\\.${octet}\\.${octet}\\.${octet}$`);
++return+regex.test(str);
}|287814|entityMap^0|0|0|0|3|E|8|X|7|0|2|7|0|0|0|7|9|9|0|0|B|D|9|0|0|B|D|9|0|0|B|D|6|0|0|1|3|1|0|0|0|0|5|8|A|P|3|V|2|0|0^^$0|@$1|2|3|4|5|6|7|1A|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1B|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|1C|8|@$F|1D|G|1E|H|I]|$F|1F|G|1G|H|J]|$F|1H|G|1I|H|J]]|9|@]|A|$]]|$1|K|3|L|5|6|7|1J|8|@$F|1K|G|1L|H|J]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|1M|8|@]|9|@]|A|$]]|$1|N|3|O|5|P|7|1N|8|@$F|1O|G|1P|H|J]|$F|1Q|G|1R|H|J]]|9|@]|A|$]]|$1|Q|3|R|5|P|7|1S|8|@$F|1T|G|1U|H|J]|$F|1V|G|1W|H|J]]|9|@]|A|$]]|$1|S|3|T|5|P|7|1X|8|@$F|1Y|G|1Z|H|J]|$F|20|G|21|H|J]]|9|@]|A|$]]|$1|U|3|V|5|P|7|22|8|@$F|23|G|24|H|J]|$F|25|G|26|H|J]]|9|@]|A|$]]|$1|W|3|X|5|P|7|27|8|@$F|28|G|29|H|J]|$F|2A|G|2B|H|J]]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|2C|8|@]|9|@]|A|$]]|$1|Z|3|10|5|11|7|2D|8|@]|9|@]|A|$12|13]]|$1|14|3|15|5|6|7|2E|8|@$F|2F|G|2G|H|I]|$F|2H|G|2I|H|J]|$F|2J|G|2K|H|J]|$F|2L|G|2M|H|J]]|9|@]|A|$]]|$1|16|3|17|5|11|7|2N|8|@]|9|@]|A|$12|13]]|$1|18|3|-4|5|6|7|2O|8|@]|9|@]|A|$]]]|19|$]]

Below Solution doesn't accept Padding Zeros

Here is the cleanest way to validate an IP Address, Let's break it down:

Fact: a valid IP Address is has <code>4 octets</code>, each octets can be a number between <code>0 - 255</code>

Breakdown of Regex that matches any value between <code>0 - 255</code>

<ul>
<li><code>25[0-5]</code> matches <code>250 - 255</code></li>
<li><code>2[0-4][0-9]</code> matches <code>200 - 249</code></li>
<li><code>1[0-9][0-9]</code> matches <code>100 - 199</code></li>
<li><code>[1-9][0-9]?</code> matches <code>1 - 99</code></li>
<li><code>0</code> matches <code>0</code></li>
</ul>

<pre class="lang-js prettyprint-override"><code>const octet = '(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]?|0)';
</code></pre>

Notes: When using <code>new RegExp</code> you should use <code>\\.</code> instead of <code>\.</code> since string will get escaped twice. 

<pre class="lang-js prettyprint-override"><code>function isValidIP(str) {
 const octet = '(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]?|0)';
 const regex = new RegExp(`^${octet}\\.${octet}\\.${octet}\\.${octet}$`);
 return regex.test(str);
}
</code></pre>

blocks|key|288699|text|简单方法|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|288700|const+invalidIp+=+ipAddress
+++.split(".")
+++.map(ip+=>+Number(ip)+>=+0+&&+Number(ip)+<=+255)
+++.includes(false);

if(invalidIp){
+//+IP+address+is+invalid
+//+throw+error+here
}|code-block|syntax|javascript|288701|entityMap^0|0|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

Simple Method

<pre><code>const invalidIp = ipAddress
 .split(".")
 .map(ip =&gt; Number(ip) &gt;= 0 &amp;&amp; Number(ip) &lt;= 255)
 .includes(false);

if(invalidIp){
 // IP address is invalid
 // throw error here
}
</code></pre>

blocks|key|3004694|text|这就是我所做的，它速度很快，效果很好：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3004695|function+isIPv4Address(inputString)+{
++++let+regex+=+new+RegExp(/%5E(([0-9]{1,3}\.){3}[0-9]{1,3})$/);
++++if(regex.test(inputString)){
++++++++let+arInput+=+inputString.split(".")
++++++++for(let+i+of+arInput){
++++++++++++if(i.length+>+1+&&+i.charAt(0)+===+'0')
++++++++++++++++return+false;
++++++++++++else{
++++++++++++++++if(parseInt(i)+<+0+%7C%7C+parseInt(i)+>=256)
+++++++++++++++++++return+false;
++++++++++++}
++++++++}
++++}
++++else
++++++++return+false;
++++return+true;
}|code-block|syntax|javascript|3004696|说明:首先，用正则表达式检查IP格式是否正确。不过，正则表达式不会检查任何值范围。|3004697|我的意思是，如果您可以使用Javascript来管理regex，为什么不使用它呢？因此，不要使用疯狂的正则表达式，而是只使用正则表达式检查格式是否正确，然后检查八位字节中的每个值是否在正确的值范围内(0到255)。希望这对任何人都有帮助。和平。|3004698|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

This is what I did and it's fast and works perfectly:

<pre><code>function isIPv4Address(inputString) {
 let regex = new RegExp(/^(([0-9]{1,3}\.){3}[0-9]{1,3})$/);
 if(regex.test(inputString)){
 let arInput = inputString.split(".")
 for(let i of arInput){
 if(i.length &gt; 1 &amp;&amp; i.charAt(0) === '0')
 return false;
 else{
 if(parseInt(i) &lt; 0 || parseInt(i) &gt;=256)
 return false;
 }
 }
 }
 else
 return false;
 return true;
}
</code></pre>

Explanation: First, with the regex check that the IP format is correct. Although, the regex won't check any value ranges.

I mean, if you can use Javascript to manage regex, why not use it?. So, instead of using a crazy regex, use Regex only for checking that the format is fine and then check that each value in the octet is in the correct value range (0 to 255). Hope this helps anybody else. Peace.

blocks|key|3218296|text|答案在Ip地址中允许前导零，并且它是不正确的。例如(“123.045.067.089”应该返回false)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3218297|正确的方法就是这样做。|3218298|+function+isValidIP(ipaddress)+{++
if+(/%5E(25[0-5]%7C2[0-4][0-9]%7C[1]?[1-9][1-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[1]?[1-9][1-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[1]?[1-9][1-9]?)\.(25[0-5]%7C2[0-4][0-9]%7C[1]?[1-9][1-9]?)$/.test(ipaddress))+{++
++return+(true)++
}+++
return+(false)+}+|code-block|syntax|javascript|3218299|此函数不允许零作为前导IP地址。|3218300|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

The answers over allow leading zeros in Ip address, and that it is not correct.
For example (&quot;123.045.067.089&quot;should return false).
The correct way to do it like that.
<pre><code> function isValidIP(ipaddress) { 
if (/^(25[0-5]|2[0-4][0-9]|[1]?[1-9][1-9]?)\.(25[0-5]|2[0-4][0-9]|[1]?[1-9][1-9]?)\.(25[0-5]|2[0-4][0-9]|[1]?[1-9][1-9]?)\.(25[0-5]|2[0-4][0-9]|[1]?[1-9][1-9]?)$/.test(ipaddress)) { 
 return (true) 
} 
return (false) } 
</code></pre>
This function will not allow zero to lead IP addresses.

blocks|key|288708|text|除了不使用正则表达式的解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|288709|​|288710|const+checkValidIpv4+=+(entry)+=>+{
++const+mainPipeline+=+[
++++block+=>+!isNaN(parseInt(block,+10)),
++++block+=>+parseInt(block,10)+>=+0,
++++block+=>+parseInt(block,10)+<=+255,
++++block+=>+String(block).length+===+1
++++++%7C%7C+String(block).length+>+1
++++++&&+String(block)[0]+!==+'0',
++];

++const+blocks+=+entry.split(".");
++if(blocks.length+===+4
++++&&+!blocks.every(block+=>+parseInt(block,+10)+===+0))+{
++++return+blocks.every(block+=>
++++++mainPipeline.every(ckeck+=>+ckeck(block)+)
++++);
++}

++return+false;
}

console.log(checkValidIpv4('0.0.0.0'));+//false
console.log(checkValidIpv4('0.0.0.1'));+//true
console.log(checkValidIpv4('0.01.001.0'));+//false
console.log(checkValidIpv4('8.0.8.0'));+//true|code-block|syntax|javascript|288711|288712|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|K|$]]

In addition to a solution without regex:
<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 checkValidIpv4 = (entry) =&gt; {
 const mainPipeline = [
 block =&gt; !isNaN(parseInt(block, 10)),
 block =&gt; parseInt(block,10) &gt;= 0,
 block =&gt; parseInt(block,10) &lt;= 255,
 block =&gt; String(block).length === 1
 || String(block).length &gt; 1
 &amp;&amp; String(block)[0] !== '0',
 ];

 const blocks = entry.split(".");
 if(blocks.length === 4
 &amp;&amp; !blocks.every(block =&gt; parseInt(block, 10) === 0)) {
 return blocks.every(block =&gt;
 mainPipeline.every(ckeck =&gt; ckeck(block) )
 );
 }

 return false;
}

console.log(checkValidIpv4('0.0.0.0')); //false
console.log(checkValidIpv4('0.0.0.1')); //true
console.log(checkValidIpv4('0.01.001.0')); //false
console.log(checkValidIpv4('8.0.8.0')); //true</code></pre>
</div>
</div>

I have several ip addresses like:

<ol>
<li><code>115.42.150.37</code></li>
<li><code>115.42.150.38</code></li>
<li><code>115.42.150.50</code></li>
</ol>

What type of regular expression should I write if I want to search for the all the 3 ip addresses? Eg, if I do <code>115.42.150.*</code> (I will be able to search for all 3 ip addresses)

What I can do now is something like: <code>/[0-9]{1-3}\.[0-9]{1-3}\.[0-9]{1-3}\.[0-9]{1-3}/</code> but it can't seems to work well. 

Thanks.

javascript regular expression to check for IP addresses

单元测试

我有几个ip地址，例如：115.42.150.37115.42.150.38115.42.150.50如果要搜索所有3个ip地址，我应该编写哪种类型的正则表达式？例如，如果我使用115.42.150.* (我将能够搜索所有3个ip地址)我现在能做的是：/[0-9]{1-3}\.[0-9]{1-3}\.[0-9]{1-3...

问用于检查IP地址的javascript正则表达式
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