RegExp

绝地灬酷狼 2022-06-12 04:46 109阅读 0赞

`RegExp` 构造函数创建了一个正则表达式对象，用于将文本与一个模式匹配。

有关正则表达式的介绍，请阅读 [JavaScript指南][JavaScript]中的[正则表达式章节][Link 1]。

## 语法[EDIT][] ##

字面量, 构造函数和工厂符号都是可以的：

/pattern/flags
    new RegExp(pattern [, flags])
    RegExp(pattern [, flags])

### 参数 ###

`pattern`

正则表达式的文本。

`flags`

如果指定，标志可以具有以下值的任意组合：

`g`

全局匹配;找到所有匹配，而不是在第一个匹配后停止

`i`

忽略大小写

`m`

多行; 将开始和结束字符（^和$）视为在多行上工作（例如，分别匹配每一行的开始和结束（由 \\n 或 \\r 分割），而不只是只匹配整个输入字符串的最开始和最末尾处。

Unicode; 将模式视为Unicode序列点的序列

`y`

粘性匹配; 仅匹配目标字符串中此正则表达式的lastIndex属性指示的索引(并且不尝试从任何后续的索引匹配)。

## 描述[EDIT][EDIT 1] ##

有两种方法来创建一个RegExp对象：一是字面量、二是构造函数。要指示字符串，字面量的参数不使用引号，而构造函数的参数使用引号。因此，以下表达式创建相同的正则表达式：

/ab+c/i;
    new RegExp('ab+c', 'i');
    new RegExp(/ab+c/, 'i');

当表达式被赋值时，字面量形式提供正则表达式的编译（compilation）状态，当正则表达式保持为常量时使用字面量。例如当你在循环中使用字面量构造一个正则表达式时，正则表达式不会在每一次迭代中都被重新编译（recompiled）。

而正则表达式对象的构造函数，如 `new RegExp('ab+c')` 提供了正则表达式运行时编译（runtime compilation）。如果你知道正则表达式模式将会改变，或者你事先不知道什么模式，而是从另一个来源获取，如用户输入，这些情况都可以使用构造函数。

从ECMAScript 6开始，当第一个参数为正则表达式而第二个标志参数存在时，new RegExp(/ab+c/, 'i')不再抛出[`TypeError`][TypeError] （“当从其他正则表达式进行构造时不支持标志”）的异常，取而代之，将使用这些参数创建一个新的正则表达式。

当使用构造函数创造正则对象时，需要常规的字符转义规则（在前面加反斜杠 \\）。比如，以下是等价的：

var re = new RegExp("\\w+");
    var re = /\w+/;

## 正则表达式中特殊字符的含义[EDIT][EDIT 2] ##

*  [字符类别（Character Classes）][Character Classes]
 *  [字符集合（Character Sets）][Character Sets]
 *  [边界（Boundaries）][Boundaries]
 *  [分组（grouping）与反向引用（back references）][grouping_back references]
 *  [数量词（Quantifiers）][Quantifiers]

<table style="margin:0px 0px 20px; padding:0px; border-collapse:collapse; width:678px"> 
 <tbody style="margin:0px; padding:0px; border:0px"> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <th colspan="2" style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符类别（Character Classes）</th> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符</th> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 含义</th> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">.</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> (点号，小数点) 匹配任意单个字符，但是行结束符除外：<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\n</code>&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\r</code>&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\u2028</code>&nbsp;或&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\u2029</code>。 在字符集中，点( . )失去其特殊含义，并匹配一个字面点( . )。 需要注意的是，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">m</code>&nbsp;多行（multiline）标志不会改变点号的表现。因此为了匹配多行中的字符集，可使用<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^]</code>&nbsp;（当然你不是打算用在旧版本 IE 中），它将会匹配任意字符，包括换行符。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/.y/</code>&nbsp;匹配 "yes make my day" 中的&nbsp;"my" 和 "ay"，但是不匹配 "yes"。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\d</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配任意阿拉伯数字。等价于<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[0-9]</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\d/</code>&nbsp;或&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/[0-9]/</code>&nbsp;匹配 "B2 is the suite number." 中的&nbsp;'2'。&nbsp; </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\D</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配任意一个不是阿拉伯数字的字符。等价于<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^0-9]</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\D/</code>&nbsp;或&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/[^0-9]/</code>&nbsp;匹配 "B2 is the suite number." 中的&nbsp;'B'。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\w</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配任意来自基本拉丁字母表中的字母数字字符，还包括下划线。等价于&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[A-Za-z0-9_]</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\w/</code>&nbsp;匹配 "apple" 中的 'a'，"$5.28" 中的 '5' 和 "3D" 中的 '3'。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\W</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配任意不是基本拉丁字母表中单词（字母数字下划线）字符的字符。等价于&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^A-Za-z0-9_]</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\W/</code>&nbsp;或&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/[^A-Za-z0-9_]/</code>&nbsp;匹配 "50%" 中的 '%'。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\s</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个空白符，包括空格、制表符、换页符、换行符和其他 Unicode 空格。 等价于&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[ \f\n\r\t\v\u00a0\u1680\u180e\u2000\u2001\u2002\u2003\u2004 \u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f \u3000]。</code> 例如&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\s\w*/</code>&nbsp;匹配 "foo bar" 中的 ' bar'。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\S</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个非空白符。等价于&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^ \f\n\r\t\v\u00a0\u1680\u180e\u2000\u2001\u2002\u2003\u2004&nbsp;\u2005\u2006\u2007\u2008\u2009\u200a\u2028\u2029\u202f\u205f\u3000]</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\S\w*/</code>&nbsp;匹配 "foo bar" 中的 'foo'。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\t</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个水平制表符（tab）</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\r</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个回车符（carriage return）</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\n</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个换行符（linefeed）</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\v</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个垂直制表符（vertical tab）</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\f</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个换页符（form-feed）</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[\b]</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个退格符（backspace）（不要与&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\b</code>&nbsp;混淆）</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\0</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个 NUL 字符。不要在此后面跟小数点。</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\cX</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">X</code>&nbsp;是 A - Z 的一个字母。匹配字符串中的一个控制字符。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\cM/</code>&nbsp;匹配字符串中的 control-M。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\xhh</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配编码为&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">hh</code>&nbsp;（两个十六进制数字）的字符。</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\uhhhh</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配 Unicode 值为&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">hhhh</code>&nbsp;（四个十六进制数字）的字符。</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 对于那些通常被认为字面意义的字符来说，表示下一个字符具有特殊用处，并且不会被按照字面意义解释。 例如&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/b/</code>&nbsp;匹配字符 'b'。在 b 前面加上一个反斜杠，即使用&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\b/</code>，则该字符变得特殊，以为这匹配一个单词边界。 或 对于那些通常特殊对待的字符，表示下一个字符不具有特殊用途，会被按照字面意义解释。 例如，* 是一个特殊字符，表示匹配某个字符 0 或多次，如&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/a*/</code>&nbsp;意味着 0 或多个 "a"。 为了匹配字面意义上的&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">*</code>&nbsp;，在它前面加上一个反斜杠，例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/a\*/</code>匹配 'a*'。 </td> 
 </tr> 
 </tbody> 
 <tbody style="margin:0px; padding:0px; border:0px"> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <th colspan="2" style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符集合（Character Sets）</th> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符</th> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 含义</th> 
 </tr> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[xyz]</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 一个字符集合，也叫字符组。匹配集合中的任意一个字符。你可以使用连字符'-'指定一个范围。 例如，[abcd] 等价于 [a-d]，匹配"brisket"中的'b'和"chop"中的'c'。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^xyz]</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 一个反义或补充字符集，也叫反义字符组。也就是说，它匹配任意不在括号内的字符。你也可以通过使用连字符 '-' 指定一个范围内的字符。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^abc]</code>&nbsp;等价于&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[^a-c]。</code>&nbsp;第一个匹配的是 "bacon" 中的'o' 和 "chop" 中的 'h'。 </td> 
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 <th colspan="2" style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 边界（Boundaries）</th> 
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 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符</th> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 含义</th> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">^</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配输入开始。如果多行（multiline）标志被设为 true，该字符也会匹配一个断行（line break）符后的开始处。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/^A/</code>&nbsp;不匹配 "an A" 中的 "A"，但匹配 "An A" 中的 "A"。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">$</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配输入结尾。如果多行（multiline）标志被设为 true，该字符也会匹配一个断行（line break）符的前的结尾处。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/t$/</code>&nbsp;不匹配 "eater" 中的 "t"，但匹配 "eat" 中的 "t"。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\b</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个零宽单词边界（zero-width word boundary），如一个字母与一个空格之间。 （不要和&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[\b]</code>&nbsp;混淆） 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\bno/</code>&nbsp;匹配 "at noon" 中的 "no"，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/ly\b/</code>&nbsp;匹配 "possibly yesterday." 中的 "ly"。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\B</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配一个零宽非单词边界（zero-width non-word boundary），如两个字母之间或两个空格之间。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\Bon/</code>&nbsp;匹配 "at noon" 中的 "on"，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/ye\B/</code>&nbsp;匹配 "possibly yesterday." 中的 "ye"。 </td> 
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 <th colspan="2" style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 分组（Grouping）与反向引用（back references）</th> 
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 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符</th> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 含义</th> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">(x)</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>&nbsp;并且捕获匹配项。 这被称为捕获括号（capturing parentheses）。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/(foo)/</code>&nbsp;匹配且捕获 "foo bar." 中的 "foo"。被匹配的子字符串可以在结果数组的元素&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[1], ..., [n]</code>&nbsp;中找到，或在被定义的&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">RegExp</code>&nbsp;对象的属性&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">$1, ..., $9</code>&nbsp;中找到。 捕获组（Capturing groups）有性能惩罚。如果不需再次访问被匹配的子字符串，最好使用非捕获括号（non-capturing parentheses），见下面。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">\n</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">n</code>&nbsp;是一个正整数。一个反向引用（back reference），指向正则表达式中第 n 个括号（从左开始数）中匹配的子字符串。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/apple(,)\sorange\1/</code>&nbsp;匹配 "apple, orange, cherry, peach." 中的 "apple,orange,"。一个更全面的例子在该表格下面。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">(?:x)</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>&nbsp;不会捕获匹配项。这被称为非捕获括号（non-capturing parentheses）。匹配项不能够从结果数组的元素&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">[1], ..., [n]</code>&nbsp;或已被定义的&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">RegExp</code>&nbsp;对象的属性&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">$1, ..., $9</code>&nbsp;再次访问到。</td> 
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 <th colspan="2" style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 数量词（Quantifiers）</th> 
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 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 字符</th> 
 <th style="margin:0px; padding:5px; border:1px solid rgb(212,221,228); font-style:inherit; font-weight:inherit; text-align:left"> 含义</th> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x*</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配前面的模式&nbsp;x&nbsp;0 或多次。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/bo*/</code>&nbsp;匹配 "A ghost booooed" 中的 "boooo"，"A bird warbled" 中的 "b"，但是不匹配 "A goat grunted"。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x+</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配前面的模式&nbsp;x&nbsp;1 或多次。等价于&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">{1,}</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/a+/</code>&nbsp;匹配 "candy" 中的 "a"，"caaaaaaandy" 中所有的 "a"。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x*?</code> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x+?</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 像上面的 * 和 + 一样匹配前面的模式&nbsp;x，然而匹配是最小可能匹配。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/".*?"/</code>&nbsp;匹配 '"foo" "bar"' 中的 '"foo"'，而 * 后面没有 ? 时匹配 '"foo" "bar"'。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x?</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配前面的模式&nbsp;x&nbsp;0 或 1 次。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/e?le?/</code>&nbsp;匹配 "angel" 中的 "el"，"angle" 中的 "le"。 如果在数量词&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">*</code>、<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">+</code>、<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">?</code>&nbsp;或&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">{}</code>, 任意一个后面紧跟该符号（?），会使数量词变为非贪婪（ non-greedy） ，即匹配次数最小化。反之，默认情况下，是贪婪的（greedy），即匹配次数最大化。 在使用于向前断言（lookahead assertions）时，见该表格中&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">(?=)、</code><code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">(?!)</code>&nbsp;和&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">(?:)</code>&nbsp;的说明。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x(?=y)</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 只有当&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>&nbsp;后面紧跟着&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">y</code>&nbsp;时，才匹配&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/Jack(?=Sprat)/</code>&nbsp;只有在 'Jack' 后面紧跟着 'Sprat' 时，才会匹配它。<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/Jack(?=Sprat|Frost)/</code>&nbsp;只有在 'Jack' 后面紧跟着 'Sprat' 或 'Frost' 时，才会匹配它。然而，'Sprat' 或 'Frost' 都不是匹配结果的一部分。</td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x(?!y)</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 只有当&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>&nbsp;后面不是紧跟着&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">y</code>&nbsp;时，才匹配&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>。例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\d+(?!\.)/</code>&nbsp;只有当一个数字后面没有紧跟着一个小数点时，才会匹配该数字。 <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/\d+(?!\.)/.exec("3.141")</code>&nbsp;匹配 141 而不是 3.141。 </td> 
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 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x|y</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> 匹配&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x</code>&nbsp;或&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">y</code> 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/green|red/</code>&nbsp;匹配 "green apple" 中的 ‘green'，"red apple." 中的 'red'。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x{ n}</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">n</code>&nbsp;是一个正整数。前面的模式&nbsp;x&nbsp;连续出现 n 次时匹配。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/a{2}/</code>&nbsp;不匹配 "candy," 中的 "a"，但是匹配 "caandy," 中的两个 "a"，且匹配 "caaandy." 中的前两个 "a"。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x{ n,}</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">n</code>&nbsp;是一个正整数。前面的模式&nbsp;x&nbsp;连续出现至少 n 次时匹配。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/a{2,}/</code>&nbsp;不匹配 "candy" 中的 "a"，但是匹配 "caandy" 和 "caaaaaaandy." 中所有的 "a"。 </td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">x{ n,m}</code></td> 
 <td style="margin:0px; padding:5px; border:1px solid rgb(204,204,204); vertical-align:top"> <code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">n</code>&nbsp;和&nbsp;<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">m</code>&nbsp;为正整数。前面的模式 x 连续出现至少 n 次，至多 m 次时匹配。 例如，<code style="word-wrap:break-word; margin:0px; padding:0px; border:0px; font-style:inherit; font-weight:inherit; font-family:consolas,&quot;Liberation Mono&quot;,courier,monospace">/a{1,3}/</code>&nbsp;不匹配 "cndy"，匹配 "candy," 中的 "a"，"caandy," 中的两个 "a"，匹配 "caaaaaaandy" 中的前面三个 "a"。注意，当匹配 "caaaaaaandy" 时，即使原始字符串拥有更多的 "a"，匹配项也是 "aaa"。 </td> 
 </tr> 
 </tbody> 
</table>

1.  [^][Link 2]等价于:
    
    `[\t\n\v\f\r \u00a0\u2000\u2001\u2002\u2003\u2004\u2005\u2006\u2007\u2008\u2009\u200a\u200b\u2028\u2029\u3000]`

### 属性 ###

For properties available on `RegExp` instances, see [Properties of RegExp instances][].

[`RegExp.prototype`][RegExp.prototype]

允许为所有正则对象添加属性。

RegExp.length

`RegExp.length` 值为 2。

Properties inherited from [`Function`][Function]:

[`arity`][arity],  [`caller`][caller],  [`constructor`][constructor],  [`length`][length],  [`name`][name]

### 方法 ###

For methods available on `RegExp` instances, see [Methods of RegExp instances][].

全局对象   `RegExp`  自身没有方法, 不过它会继承一些方法通过原型链

Methods inherited from [`Function`][Function]:

[`apply`][apply],  [`call`][call],  [`toSource`][toSource],  [`toString`][toString]

## RegExp 实例[EDIT][EDIT 3] ##

### 属性 ###

查看[已废弃的RegExp属性][RegExp]

注意，`RegExp` 对象的几个属性既有完整的长属性名，也有对应的类 Perl 的短属性名。两个属性都有着同样的值。JavaScript 的正则语法就是基于 Perl 的。

`RegExp.prototype.` `constructor`

创建该正则对象的构造函数。

[`RegExp.prototype.global`][RegExp.prototype.global]

是否开启全局匹配，也就是匹配目标字符串中所有可能的匹配项，而不是只进行第一次匹配。

[`RegExp.prototype.ignoreCase`][RegExp.prototype.ignoreCase]

在匹配字符串时是否要忽略字符的大小写。

[`RegExp.prototype.lastIndex`][RegExp.prototype.lastIndex]

下次匹配开始的字符串索引位置。

[`RegExp.prototype.multiline`][RegExp.prototype.multiline]

是否开启多行模式匹配（影响 ^ 和 $ 的行为）。

[`RegExp.prototype.source`][RegExp.prototype.source]

正则对象的源模式文本。

[`RegExp.prototype.sticky`][RegExp.prototype.sticky]

是否开启粘滞匹配。

Properties inherited from [`Object`][Object]:

[`__parent__`][parent],  [`__proto__`][proto]

### 方法 ###

查看[已废弃的RegExp方法][RegExp 1]

[`RegExp.prototype.exec()`][RegExp.prototype.exec]

在目标字符串中执行一次正则匹配操作。

[`RegExp.prototype.test()`][RegExp.prototype.test]

测试当前正则是否能匹配目标字符串。

[`RegExp.prototype.toSource()`][RegExp.prototype.toSource]

返回一个字符串，其值为该正则对象的字面量形式。覆盖了 `Object.prototype.toSource` 方法.

[`RegExp.prototype.toString()`][RegExp.prototype.toString]

返回一个字符串，其值为该正则对象的字面量形式。覆盖了 [`Object.prototype.toString()`][Object.prototype.toString] 方法。

Methods inherited from [`Object`][Object]:

[`__defineGetter__`][defineGetter],  [`__defineSetter__`][defineSetter],  [`hasOwnProperty`][hasOwnProperty],  [`isPrototypeOf`][isPrototypeOf],  [`__lookupGetter__`][lookupGetter],  [`__lookupSetter__`][lookupSetter],  [`__noSuchMethod__`][noSuchMethod],  [`propertyIsEnumerable`][propertyIsEnumerable],  [`toLocaleString`][toLocaleString],  [`unwatch`][unwatch],  [`valueOf`][valueOf],  [`watch`][watch]

## 例子[EDIT][EDIT 4] ##

### 例子：使用正则改变数据结构 ###

下例使用 [`replace`][replace] 方法 （继承自 [`String`][String]）去匹配姓名 first last 输出新的格式 last, first。脚本中使用 `$1 和` `$2` 指明括号里先前的匹配.

var re = /(\w+)\s(\w+)/;
    var str = "John Smith";
    var newstr = str.replace(re, "$2, $1");
    print(newstr);

显示 "Smith, John".

### 例子：在多行中使用正则表达式 ###

var s = "Please yes\nmake my day!";
    s.match(/yes.*day/);
    // Returns null
    s.match(/yes[^]*day/);
    // Returns 'yes\nmake my day'

### 例子: 使用带有 ”sticky“ 标志的正则表达式 ###

该例展示了，如何在正则表达式上使用 sticky 标志，用来匹配多行输入的单独行。

var text = "First line\nsecond line";
    var regex = /(\S+) line\n?/y;
    
    var match = regex.exec(text);
    print(match[1]);  // prints "First"
    print(regex.lastIndex); // prints 11
    
    var match2 = regex.exec(text);
    print(match2[1]); // prints "Second"
    print(regex.lastIndex); // prints "22"
    
    var match3 = regex.exec(text);
    print(match3 === null); // prints "true"

可以使用 `try { … } catch { … }` 来测试运行时（run-time）是否支持 `sticky` 标志。这种情况下，必须使用 `eval(…)` 表达式或 `RegExp(regex-string, flags-string)` 语法（这是由于 `/regex/flags` 表示法将会在编译时刻被处理，因此在 `catch` 语句块处理异常前就会抛出一个异常。例如：

var supports_sticky;
    try {  RegExp('','y'); supports_sticky = true; }
    catch(e) {  supports_sticky = false; }
    alert(supports_sticky); // alerts "false" in Firefox 2, "true" in Firefox 3+

### 例子：使用正则表达式和 Unicode 字符 ###

正如上面表格提到的，`\w` 或 `\W` 只会匹配基本的 ASCII 字符；如 'a' 到 'z'、 'A' 到 'Z'、 0 到 9 及 '\_'。为了匹配其他语言中的字符，如西里尔（Cyrillic）或 希伯来语（Hebrew），要使用 `\uhhhh`，"hhhh" 表示以十六进制表示的字符的 Unicode 值。下例展示了怎样从一个单词中分离出 Unicode 字符。

var text = "Образец text на русском языке";
    var regex = /[\u0400-\u04FF]+/g;
    
    var match = regex.exec(text);
    print(match[1]);  // prints "Образец"
    print(regex.lastIndex);  // prints "7"
    
    var match2 = regex.exec(text);
    print(match2[1]);  // prints "на" [did not print "text"]
    print(regex.lastIndex);  // prints "15"
    
    // and so on

这里有一个外部资源，用来获取 Unicode 中的不同区块范围：[Regexp-unicode-block][]

### 例子：从 URL 中提取子域名 ###

var url = "http://xxx.domain.com";
    print(/[^.]+/.exec(url)[0].substr(7)); // prints "xxx"

## 规范[EDIT][EDIT 5] ##

<table style="margin:0px 0px 24px; padding:0px; border:2px solid rgb(255,255,255); border-collapse:collapse"> 
 <tbody style="margin:0px; padding:0px; border:0px"> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <th style="margin:0px; padding:2px 8px 4px; border-width:2px; border-style:solid; border-color:rgb(255,255,255) rgb(255,255,255) rgb(212,221,228); font-style:inherit; text-align:left; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:14px"> Specification</th> 
 <th style="margin:0px; padding:2px 8px 4px; border-width:2px; border-style:solid; border-color:rgb(255,255,255) rgb(255,255,255) rgb(212,221,228); font-style:inherit; text-align:left; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:14px"> Status</th> 
 <th style="margin:0px; padding:2px 8px 4px; border-width:2px; border-style:solid; border-color:rgb(255,255,255) rgb(255,255,255) rgb(212,221,228); font-style:inherit; text-align:left; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:14px"> Comment</th> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">ECMAScript 1st Edition. Implemented in JavaScript 1.1</td> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">Standard</td> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">Initial definition.</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)"><a href="http://www.ecma-international.org/ecma-262/5.1/#sec-15.10" style="color:rgb(33,122,192); text-decoration:none; margin:0px; padding:0px; border:0px; white-space:pre-line" rel="nofollow">ECMAScript 5.1 (ECMA-262) RegExp</a></td> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">Standard</td> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">&nbsp;</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)"><a href="http://www.ecma-international.org/ecma-262/6.0/#sec-regexp-regular-expression-objects" style="color:rgb(33,122,192); text-decoration:none; margin:0px; padding:0px; border:0px; white-space:pre-line" rel="nofollow">ECMAScript 2015 (6th Edition, ECMA-262) RegExp</a></td> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">Standard</td> 
 <td style="margin:0px; padding:6px 8px; border:2px solid rgb(255,255,255)">&nbsp;</td> 
 </tr> 
 </tbody> 
</table>

## 浏览器兼容性[EDIT][EDIT 6] ##

*  Desktop 
 *  Mobile

<table style="margin:0px; padding:0px; border-width:1px 0px 0px 1px; border-style:solid; border-color:transparent; border-collapse:collapse"> 
 <tbody style="margin:0px; padding:0px; border:0px"> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <th style="margin:0px; padding:2px 4px 8px; border:none; font-style:inherit; font-weight:200; text-align:left; background:0px 0px; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:16px; line-height:16px"> Feature</th> 
 <th style="margin:0px; padding:2px 4px 8px; border:none; font-style:inherit; font-weight:200; text-align:left; background:0px 0px; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:16px; line-height:16px"> Chrome</th> 
 <th style="margin:0px; padding:2px 4px 8px; border:none; font-style:inherit; font-weight:200; text-align:left; background:0px 0px; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:16px; line-height:16px"> Firefox (Gecko)</th> 
 <th style="margin:0px; padding:2px 4px 8px; border:none; font-style:inherit; font-weight:200; text-align:left; background:0px 0px; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:16px; line-height:16px"> Internet Explorer</th> 
 <th style="margin:0px; padding:2px 4px 8px; border:none; font-style:inherit; font-weight:200; text-align:left; background:0px 0px; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:16px; line-height:16px"> Opera</th> 
 <th style="margin:0px; padding:2px 4px 8px; border:none; font-style:inherit; font-weight:200; text-align:left; background:0px 0px; font-family:&quot;Open Sans Light&quot;,Helvetica,arial,sans-serif; font-size:16px; line-height:16px"> Safari</th> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> Basic support</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> (Yes)</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> (Yes)</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> (Yes)</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> (Yes)</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> (Yes)</td> 
 </tr> 
 <tr style="margin:0px; padding:0px; border:0px"> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> Sticky flag ("y")</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> ?</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> <a href="https://developer.mozilla.org/en-US/Firefox/Releases/3" title="Released on 2008-06-17." style="color:rgb(33,122,192); text-decoration:none; margin:0px; padding:0px; border:0px" rel="nofollow">3.0</a>&nbsp;(1.9)</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> ?</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> ?</td> 
 <td style="margin:0px; padding:5px; background:rgb(255,255,255); vertical-align:top; word-wrap:break-word"> ?</td> 
 </tr> 
 </tbody> 
</table>

\[1\] Behind a flag.

\[2\] At least from version 41.

## Gecko-特定的 注释[EDIT][EDIT 7] ##

Starting with Gecko 34 (Firefox 34 / Thunderbird 34 / SeaMonkey 2.31), in the case of a capturing group with quantifiers preventing its exercise, the matched text for a capturing group is now `undefined` instead of an empty string:

// Firefox 33 or older
    'x'.replace(/x(.)?/g, function(m, group) {
      console.log("'group:" + group + "'");
    }); // 'group:'
    
    // Firefox 34 or newer
    'x'.replace(/x(.)?/g, function(m, group) {
      console.log("'group:" + group + "'");
    }); // 'group:undefined'

Note that due to web compatibility, `RegExp.$N` will still return an empty string instead of `undefined` ([bug 1053944][bug_1053944]).

## 相关链接[EDIT][EDIT 8] ##

*  [Regular Expressions][] chapter in the [JavaScript Guide][]
 *  [String.prototype.match()][String.prototype.match]
 *  [String.prototype.replace()][String.prototype.replace]

这篇文章有帮助吗？

是   否

谢谢！

## 文档标签和贡献者 ##

标签：

*  [RegExp][RegExp 2] 
 *  [Regular Expressions][Regular Expressions 1] 
 *  [字面量][Link 3] 
 *  [工厂符号][Link 4] 
 *  [构造函数][Link 5] 
 *  [边界字符（Boundaries）][Boundaries 1]

此页面的贡献者：  [Ende93][],  [xgqfrms-GitHub][],  [kiling][],  [biaocy][],  [fuchao2012][],  [shuata][],  [xgqfrms][],  [KingMario][],  [vbnjfhty][],  [y8n][], [tabooc][],  [jamesxu][],  [teoli][],  [AlexChao][],  [chyee][],  [Darrel.Hsu][],  [photino][],  [ziyunfei][],  [fishenal][],  [akawhy][],  [shi\_zheng][shi_zheng],  [GreatHan][],  [Hans huang][],  [Mickeyboy][]

最后编辑者:  [Ende93][], Jun 27, 2017, 2:42:27 AM

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另见

[JavaScript]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Guide/
[Link 1]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Guide/Regular_Expressions
[EDIT]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#Syntax
[EDIT 1]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#Description
[TypeError]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/TypeError
[EDIT 2]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#Special_characters_in_regular_expressions
[Character Classes]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp#character-classes
[Character Sets]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp#character-sets
[Boundaries]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp#boundaries
[grouping_back references]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp#grouping-back-references
[Quantifiers]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp#quantifiers
[Link 2]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp#ref_equivalent_s
[Properties of RegExp instances]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/prototype#Properties
[RegExp.prototype]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/prototype
[Function]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function
[arity]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Arity
[caller]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Caller
[constructor]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Constructor
[length]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Length
[name]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Name
[Methods of RegExp instances]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/prototype#Methods
[apply]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Apply
[call]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/Call
[toSource]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/ToSource
[toString]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Function/ToString
[EDIT 3]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#RegExp_实例
[RegExp]: https://developer.mozilla.org/zh-CN/docs/JavaScript/Reference/Deprecated_Features#RegExp_Properties
[RegExp.prototype.global]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/global
[RegExp.prototype.ignoreCase]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/ignoreCase
[RegExp.prototype.lastIndex]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/lastIndex
[RegExp.prototype.multiline]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/multiline
[RegExp.prototype.source]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/source
[RegExp.prototype.sticky]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/sticky
[Object]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object
[parent]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/Parent
[proto]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/Proto
[RegExp 1]: https://developer.mozilla.org/zh-CN/docs/JavaScript/Reference/Deprecated_Features#RegExp_Methods
[RegExp.prototype.exec]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/exec
[RegExp.prototype.test]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/test
[RegExp.prototype.toSource]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/toSource
[RegExp.prototype.toString]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp/toString
[Object.prototype.toString]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/toString
[defineGetter]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/DefineGetter
[defineSetter]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/DefineSetter
[hasOwnProperty]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/HasOwnProperty
[isPrototypeOf]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/IsPrototypeOf
[lookupGetter]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/LookupGetter
[lookupSetter]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/LookupSetter
[noSuchMethod]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/NoSuchMethod
[propertyIsEnumerable]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/PropertyIsEnumerable
[toLocaleString]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/ToLocaleString
[unwatch]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/Unwatch
[valueOf]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/ValueOf
[watch]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/Watch
[EDIT 4]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#例子
[replace]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String/replace
[String]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String
[Regexp-unicode-block]: http://kourge.net/projects/regexp-unicode-block
[EDIT 5]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#规范
[EDIT 6]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#Browser_Compatibility
[EDIT 7]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#Gecko-特定的_注释
[bug_1053944]: https://bugzilla.mozilla.org/show_bug.cgi?id=1053944
[EDIT 8]: https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/RegExp$edit#相关链接_2
[Regular Expressions]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
[JavaScript Guide]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide
[String.prototype.match]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/match
[String.prototype.replace]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace
[RegExp 2]: https://developer.mozilla.org/zh-CN/docs/tag/RegExp
[Regular Expressions 1]: https://developer.mozilla.org/zh-CN/docs/tag/Regular%20Expressions
[Link 3]: https://developer.mozilla.org/zh-CN/docs/tag/%E5%AD%97%E9%9D%A2%E9%87%8F
[Link 4]: https://developer.mozilla.org/zh-CN/docs/tag/%E5%B7%A5%E5%8E%82%E7%AC%A6%E5%8F%B7
[Link 5]: https://developer.mozilla.org/zh-CN/docs/tag/%E6%9E%84%E9%80%A0%E5%87%BD%E6%95%B0
[Boundaries 1]: https://developer.mozilla.org/zh-CN/docs/tag/%E8%BE%B9%E7%95%8C%E5%AD%97%E7%AC%A6%EF%BC%88Boundaries%EF%BC%89
[Ende93]: https://developer.mozilla.org/zh-CN/profiles/Ende93
[xgqfrms-GitHub]: https://developer.mozilla.org/zh-CN/profiles/xgqfrms-GitHub
[kiling]: https://developer.mozilla.org/zh-CN/profiles/kiling
[biaocy]: https://developer.mozilla.org/zh-CN/profiles/biaocy
[fuchao2012]: https://developer.mozilla.org/zh-CN/profiles/fuchao2012
[shuata]: https://developer.mozilla.org/zh-CN/profiles/shuata
[xgqfrms]: https://developer.mozilla.org/zh-CN/profiles/xgqfrms
[KingMario]: https://developer.mozilla.org/zh-CN/profiles/KingMario
[vbnjfhty]: https://developer.mozilla.org/zh-CN/profiles/vbnjfhty
[y8n]: https://developer.mozilla.org/zh-CN/profiles/y8n
[tabooc]: https://developer.mozilla.org/zh-CN/profiles/tabooc
[jamesxu]: https://developer.mozilla.org/zh-CN/profiles/jamesxu
[teoli]: https://developer.mozilla.org/zh-CN/profiles/teoli
[AlexChao]: https://developer.mozilla.org/zh-CN/profiles/AlexChao
[chyee]: https://developer.mozilla.org/zh-CN/profiles/chyee
[Darrel.Hsu]: https://developer.mozilla.org/zh-CN/profiles/Darrel.Hsu
[photino]: https://developer.mozilla.org/zh-CN/profiles/photino
[ziyunfei]: https://developer.mozilla.org/zh-CN/profiles/ziyunfei
[fishenal]: https://developer.mozilla.org/zh-CN/profiles/fishenal
[akawhy]: https://developer.mozilla.org/zh-CN/profiles/akawhy
[shi_zheng]: https://developer.mozilla.org/zh-CN/profiles/shi_zheng
[GreatHan]: https://developer.mozilla.org/zh-CN/profiles/GreatHan
[Hans huang]: https://developer.mozilla.org/zh-CN/profiles/Hans%20huang
[Mickeyboy]: https://developer.mozilla.org/zh-CN/profiles/Mickeyboy