blocks|key|1302604|text|如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1302605|str.replace(regex,+function(match,+$1,+$2,+offset,+original)+{+return+someFunc($2);+})|code-block|syntax|javascript|1302606|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|$]]

Like this:

<pre><code>str.replace(regex, function(match, $1, $2, offset, original) { return someFunc($2); })
</code></pre>

blocks|key|1087496|text|将函数作为第二个参数传递给replace|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1087497|str+=+str.replace(/(\$)([a-z]%2B)/gi,+myReplace);

function+myReplace(str,+group1,+group2)+{
++++return+"%2B"+%2B+group2+%2B+"%2B";
}|code-block|syntax|javascript|1087498|根据mozilla.org的说法，这种能力从Javascript1.3开始就已经存在了。|1087499|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/String/replace^0|D|7|0|0|2|B|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|M|3|-4|5|6|7|12|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

Pass a function as the second argument to <code>replace</code>:

<pre><code>str = str.replace(/(\$)([a-z]+)/gi, myReplace);

function myReplace(str, group1, group2) {
 return "+" + group2 + "+";
}
</code></pre>

This capability has been around since Javascript 1.3, according to <a href="https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/String/replace" rel="noreferrer">mozilla.org</a>.

blocks|key|1087571|text|使用ESNext，相当于一个虚拟链接的替代品，但只是为了展示它是如何工作的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1087572|​|1087573|let+text+=+'Visit+http://lovecats.com/new-posts/+and+https://lovedogs.com/best-dogs+NOW+!';

text+=+text.replace(/(https?:\/\/[%5E+]%2B)/g,+(match,+link)+=>+{
++//+remove+ending+slash+if+there+is+one
++link+=+link.replace(/\/?$/,+'');
++
++return+`<a+href="${link}"+target="_blank">${link.substr(link.lastIndexOf('/')+%2B1)}</a>`;
});

document.body.innerHTML+=+text;|code-block|syntax|javascript|1087574|1087575|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|$]]

Using ESNext, quite a dummy links replacer but just to show-case how it works :

<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>let text = 'Visit http://lovecats.com/new-posts/ and https://lovedogs.com/best-dogs NOW !';

text = text.replace(/(https?:\/\/[^ ]+)/g, (match, link) =&gt; {
 // remove ending slash if there is one
 link = link.replace(/\/?$/, '');
 
 return `&lt;a href="${link}" target="_blank"&gt;${link.substr(link.lastIndexOf('/') +1)}&lt;/a&gt;`;
});

document.body.innerHTML = text;</code></pre>
</div>
</div>

blocks|key|1087606|text|如果你有一个可变数量的反向引用，那么参数计数(和位置)也是可变的。MDN+Web+Docs描述了将函数指定为替换参数的以下语法：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1087607|function+replacer(match[,+p1[,+p2[,+p...]]],+offset,+string)|code-block|syntax|javascript|1087608|例如，以以下正则表达式为例：|1087609|var+searches+=+[
++++'test([1-3]){1,3}',++//+1+backreference
++++'([Ss]ome)+([A-z]%2B)+chars',++//+2+backreferences
++++'([Mm][a@]ny)+([Mm][0o]r[3e])+([Ww][0o]rd[5s])'++//+3+backreferences
];
for+(var+i+in+searches)+{
++++"Some+string+chars+and+many+m0re+w0rds+in+this+test123".replace(
++++++++new+RegExp(
++++++++++++searches[i]
++++++++++++function(...args)+{
++++++++++++++++var+match+=+args[0];
++++++++++++++++var+backrefs+=+args.slice(1,+args.length+-+2);
++++++++++++++++//+will+be:+['Some',+'string'],+['many',+'m0re',+'w0rds'],+['123']
++++++++++++++++var+offset+=+args[args.length+-+2];
++++++++++++++++var+string+=+args[args.length+-+1];
++++++++++++}
++++++++)
++++);
}|1087610|您不能在此处使用'arguments‘变量，因为它的类型为Arguments，而no的类型为Array，因此它没有slice()方法。|style|CODE|1087611|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace#Specifying_a_function_as_a_parameter^0|X|C|0|0|0|0|0|T|9|1A|5|1L|7|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|D|3|E|5|F|7|12|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|14|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|15|8|@$A|16|B|17|O|P]|$A|18|B|19|O|P]|$A|1A|B|1B|O|P]]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|1C|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]]]

If you would have a variable amount of backreferences then the argument count (and places) are also variable. The <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace#Specifying_a_function_as_a_parameter" rel="nofollow noreferrer">MDN Web Docs</a> describe the follwing syntax for sepcifing a function as replacement argument:

<pre><code>function replacer(match[, p1[, p2[, p...]]], offset, string)
</code></pre>

For instance, take these regular expressions:

<pre><code>var searches = [
 'test([1-3]){1,3}', // 1 backreference
 '([Ss]ome) ([A-z]+) chars', // 2 backreferences
 '([Mm][a@]ny) ([Mm][0o]r[3e]) ([Ww][0o]rd[5s])' // 3 backreferences
];
for (var i in searches) {
 "Some string chars and many m0re w0rds in this test123".replace(
 new RegExp(
 searches[i]
 function(...args) {
 var match = args[0];
 var backrefs = args.slice(1, args.length - 2);
 // will be: ['Some', 'string'], ['many', 'm0re', 'w0rds'], ['123']
 var offset = args[args.length - 2];
 var string = args[args.length - 1];
 }
 )
 );
}
</code></pre>

You can't use 'arguments' variable here because it's of type <code>Arguments</code> and no of type <code>Array</code> so it doesn't have a <code>slice()</code> method.

You can backreference like this in JavaScript:

<pre><code>var str = "123 $test 123";
str = str.replace(/(\$)([a-z]+)/gi, "$2");
</code></pre>

This would (quite silly) replace "$test" with "test". But imagine I'd like to pass the resulting string of $2 into a function, which returns another value. I tried doing this, but instead of getting the string "test", I get "$2". Is there a way to achieve this?

<pre><code>// Instead of getting "$2" passed into somefunc, I want "test"
// (i.e. the result of the regex)
str = str.replace(/(\$)([a-z]+)/gi, somefunc("$2"));
</code></pre>

JavaScript - string regex backreferences

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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您可以在JavaScript中像这样进行反向引用：var str = "123 $test 123";str = str.replace(/(\$)([a-z]+)/gi, "$2");这将(相当愚蠢地)将"$test“替换为"test”。但想象一下，我想要将结果字符串$2传递给一个函数，该函数返回另一个值。我试过这样...

问JavaScript - string正则表达式反向引用
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