正则表达式语法

忘是亡心i 2022-09-18 01:44 241阅读 0赞

正则表达式是一种文本模式，包括普通字符（例如，a 到 z 之间的字母）和特殊字符（称为“*元字符*”）。模式描述在搜索文本时要匹配的一个或多个字符串。

# 正则表达式示例 #

下表包含了元字符的完整列表以及它们在正则表达式上下文中的行为：

<table style="border-collapse:collapse; padding:0px; width:809px; border:1px solid rgb(187,187,187)"> 
 <tbody> 
 <tr> 
 <th style="border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; background-color:rgb(237,237,237); color:rgb(99,99,99); font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important"> 字符</th> 
 <th style="border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; background-color:rgb(237,237,237); color:rgb(99,99,99); font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important"> 说明</th> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \ </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 将下一字符标记为特殊字符、文本、反向引用或八进制转义符。例如，“n”匹配字符“n”。“\n”匹配换行符。序列“\\”匹配“\”，“\(”匹配“(”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> ^ </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配输入字符串开始的位置。如果设置了&nbsp;RegExp&nbsp;对象的&nbsp;Multiline&nbsp;属性，^ 还会与“\n”或“\r”之后的位置匹配。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> $ </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配输入字符串结尾的位置。如果设置了&nbsp;RegExp&nbsp;对象的&nbsp;Multiline&nbsp;属性，$ 还会与“\n”或“\r”之前的位置匹配。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> * </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 零次或多次匹配前面的字符或子表达式。例如，zo* 匹配“z”和“zoo”。* 等效于 {0,}。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> + </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 一次或多次匹配前面的字符或子表达式。例如，“zo+”与“zo”和“zoo”匹配，但与“z”不匹配。+ 等效于 {1,}。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> ? </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 零次或一次匹配前面的字符或子表达式。例如，“do(es)?”匹配“do”或“does”中的“do”。? 等效于 {0,1}。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> { n} </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> n&nbsp;是非负整数。正好匹配&nbsp;n&nbsp;次。例如，“o{2}”与“Bob”中的“o”不匹配，但与“food”中的两个“o”匹配。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> { n,} </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> n&nbsp;是非负整数。至少匹配&nbsp;n&nbsp;次。例如，“o{2,}”不匹配“Bob”中的“o”，而匹配“foooood”中的所有 o。“o{1,}”等效于“o+”。“o{0,}”等效于“o*”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> { n,m} </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> M&nbsp;和&nbsp;n&nbsp;是非负整数，其中&nbsp;n&nbsp;&lt;=&nbsp;m。匹配至少&nbsp;n&nbsp;次，至多&nbsp;m&nbsp;次。例如，“o{1,3}”匹配“fooooood”中的头三个 o。'o{0,1}' 等效于 'o?'。注意：您不能将空格插入逗号和数字之间。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> ? </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 当此字符紧随任何其他限定符（*、+、?、{ n}、{ n,}、{ n,m}）之后时，匹配模式是“非贪心的”。“非贪心的”模式匹配搜索到的、尽可能短的字符串，而默认的“贪心的”模式匹配搜索到的、尽可能长的字符串。例如，在字符串“oooo”中，“o+?”只匹配单个“o”，而“o+”匹配所有“o”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> . </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配除“\n”之外的任何单个字符。若要匹配包括“\n”在内的任意字符，请使用诸如“[\s\S]”之类的模式。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> (pattern) </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;pattern&nbsp;并捕获该匹配的子表达式。可以使用&nbsp;$0…$9&nbsp;属性从结果“匹配”集合中检索捕获的匹配。若要匹配括号字符 ( )，请使用“$”或者“$”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> (?:pattern) </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;pattern&nbsp;但不捕获该匹配的子表达式，即它是一个非捕获匹配，不存储供以后使用的匹配。这对于用“or”字符 (|) 组合模式部件的情况很有用。例如，'industr(?:y|ies) 是比 'industry|industries' 更经济的表达式。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> (?=pattern) </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 执行正向预测先行搜索的子表达式，该表达式匹配处于匹配&nbsp;pattern&nbsp;的字符串的起始点的字符串。它是一个非捕获匹配，即不能捕获供以后使用的匹配。例如，'Windows (?=95|98|NT|2000)' 匹配“Windows 2000”中的“Windows”，但不匹配“Windows 3.1”中的“Windows”。预测先行不占用字符，即发生匹配后，下一匹配的搜索紧随上一匹配之后，而不是在组成预测先行的字符后。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> (?!pattern) </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 执行反向预测先行搜索的子表达式，该表达式匹配不处于匹配&nbsp;pattern&nbsp;的字符串的起始点的搜索字符串。它是一个非捕获匹配，即不能捕获供以后使用的匹配。例如，'Windows (?!95|98|NT|2000)' 匹配“Windows 3.1”中的 “Windows”，但不匹配“Windows 2000”中的“Windows”。预测先行不占用字符，即发生匹配后，下一匹配的搜索紧随上一匹配之后，而不是在组成预测先行的字符后。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> x|y </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;x&nbsp;或&nbsp;y。例如，'z|food' 匹配“z”或“food”。'(z|f)ood' 匹配“zood”或“food”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> [xyz] </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 字符集。匹配包含的任一字符。例如，“[abc]”匹配“plain”中的“a”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> [^xyz] </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 反向字符集。匹配未包含的任何字符。例如，“[^abc]”匹配“plain”中的“p”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> [a-z] </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 字符范围。匹配指定范围内的任何字符。例如，“[a-z]”匹配“a”到“z”范围内的任何小写字母。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> [^a-z] </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 反向范围字符。匹配不在指定的范围内的任何字符。例如，“[^a-z]”匹配任何不在“a”到“z”范围内的任何字符。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \b </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配一个字边界，即字与空格间的位置。例如，“er\b”匹配“never”中的“er”，但不匹配“verb”中的“er”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \B </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 非字边界匹配。“er\B”匹配“verb”中的“er”，但不匹配“never”中的“er”。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \cx </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;x&nbsp;指示的控制字符。例如，\cM 匹配 Control-M 或回车符。x&nbsp;的值必须在 A-Z 或 a-z 之间。如果不是这样，则假定 c 就是“c”字符本身。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \d </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 数字字符匹配。等效于 [0-9]。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \D </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 非数字字符匹配。等效于 [^0-9]。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \f </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 换页符匹配。等效于 \x0c 和 \cL。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \n </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 换行符匹配。等效于 \x0a 和 \cJ。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \r </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配一个回车符。等效于 \x0d 和 \cM。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \s </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配任何空白字符，包括空格、制表符、换页符等。与 [&nbsp;\f\n\r\t\v] 等效。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \S </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配任何非空白字符。与 [^&nbsp;\f\n\r\t\v] 等效。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \t </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 制表符匹配。与 \x09 和 \cI 等效。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \v </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 垂直制表符匹配。与 \x0b 和 \cK 等效。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \w </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配任何字类字符，包括下划线。与“[A-Za-z0-9_]”等效。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \W </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 与任何非单词字符匹配。与“[^A-Za-z0-9_]”等效。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \xn </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;n，此处的&nbsp;n&nbsp;是一个十六进制转义码。十六进制转义码必须正好是两位数长。例如，“\x41”匹配“A”。“\x041”与“\x04”&amp;“1”等效。允许在正则表达式中使用 ASCII 代码。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \num </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;num，此处的&nbsp;num&nbsp;是一个正整数。到捕获匹配的反向引用。例如，“(.)\1”匹配两个连续的相同字符。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \n </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 标识一个八进制转义码或反向引用。如果 \n&nbsp;前面至少有&nbsp;n&nbsp;个捕获子表达式，那么&nbsp;n&nbsp;是反向引用。否则，如果&nbsp;n&nbsp;是八进制数 (0-7)，那么&nbsp;n&nbsp;是八进制转义码。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \nm </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 标识一个八进制转义码或反向引用。如果 \nm&nbsp;前面至少有&nbsp;nm&nbsp;个捕获子表达式，那么&nbsp;nm&nbsp;是反向引用。如果 \nm&nbsp;前面至少有&nbsp;n&nbsp;个捕获，则&nbsp;n&nbsp;是反向引用，后面跟有字符&nbsp;m。如果两种前面的情况都不存在，则 \nm&nbsp;匹配八进制值&nbsp;nm，其中&nbsp;n&nbsp;和&nbsp;m是八进制数字 (0-7)。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \nml </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 当&nbsp;n&nbsp;是八进制数 (0-3)，m&nbsp;和&nbsp;l&nbsp;是八进制数 (0-7) 时，匹配八进制转义码&nbsp;nml。 </td> 
 </tr> 
 <tr> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> \un </td> 
 <td style="font-family:'Microsoft YaHei UI','Microsoft YaHei',SimSun,'Segoe UI','Lucida Grande',Verdana,Arial,Helvetica,sans-serif!important; border:1px solid rgb(187,187,187); margin:10px; padding:10px 8px; color:rgb(42,42,42); vertical-align:top"> 匹配&nbsp;n，其中&nbsp;n&nbsp;是以四位十六进制数表示的 Unicode 字符。例如，\u00A9 匹配版权符号 (©)。 </td> 
 </tr> 
 </tbody> 
</table>