出處：RegExLib.com Regular Expression Cheat Sheet (.NET)
| 元字符 | 說明 |
|---|---|
| ^ | 匹配字符串的開始位置 |
| $ | 匹配字符串的結束位置 |
| . | 匹配任意單個字符（換行符 /n 除外） |
| | | 交替 |
| {…} | 指定要限定的數量 |
| [...] | 指定要匹配的字符集 |
| (…) | 對表達式進行邏輯分組 |
| * | 匹配零或多個前面的表達式 |
| + | 匹配一或多個前面的表達式 |
| ? | 匹配零或一個前面的表達式 |
| / | 放在上面任何一個字符之前，表示匹配該字符本身。放在其他特殊字符后面，表示字符轉義（見下面） |
| 字符轉義 | 說明 |
| 原始字符 | 除 . $ ^ { [ ( | ) ] } * + ? / 之外的字符均匹配自身 |
| /a | 匹配鈴聲（鬧鈴）/u0007 |
| /b | 在[]中匹配一個空格 /u0008，在其他情況下匹配字邊界（位于 /w 和 /W 字符之間） |
| /t | 匹配制表符 /u0009 |
| /r | 匹制回車符 /u000D |
| /v | 匹配垂直制表符 /u000B |
| /f | 匹配換頁符 /u000C |
| /n | 匹配換行符 /u000A |
| /e | 匹配退出鍵（符） /u001B |
| /040 | 匹配以八進制表示的 ASCII 字符（最多三位數）；在沒有前導零的情況下，如果只有一位數字或者相應數字與某個捕獲組的編號對應，那就是反向引用（backreference）。字符 /040 表示一個空格。 |
| /x20 | 匹配以十六進制表示的 ASCII 字符（兩位數） |
| /cC | 匹配 ASCII 控制符，例如 /cC 匹配 Ctrl+C |
| /u0020 | 匹配以十六進制表示的 Unicode 字符 |
| /* | 反斜杠后面如果不是一個可轉義的字符，則匹配該字符本身。例如，/* 就相當于/x2A |
| 字符類 | 說明 |
| . | 匹配除 /n 之外的任意字符。 |
| [aeiou] | 匹配特定字符集中包含的任意一個字符 |
| [^aeiou] | 匹配特定字符集中不包含的任意一個字符 |
| [0-9a-fA-F] | 連字符（-）用來指定連續的字符范圍 |
| /p{name} | 匹配由{name}指定的命名字符類中的任意字符 |
| /P{name} | 匹配不包含在{name}指定的組或塊范圍中的文本 |
| /w | 匹配英文數字字母字符，在指定兼容ECMAScript的情況下，等價于[a-zA-Z0-9] |
| /W | 匹配非英文數字字母字符，在指定兼容ECMAScript的情況下，等價于[^a-zA-Z0-9] |
| /s | 匹配任意空白字符，在指定兼容ECMAScript的情況下，等價于[/f/n/r/t/v] |
| /S | 匹配任意非空白字符，在指定兼容ECMAScript的情況下，等價于[^/f/n/r/t/v] |
| /d | 匹配數字字符，在指定兼容ECMAScript的情況下，等價于[0-9] |
| /D | 匹配非數字字符，在指定兼容ECMAScript的情況下，等價于[^0-9] |
Metacharacters Defined | |
|---|---|
| MChar | Definition |
| ^ | Start of a string. |
| $ | End of a string. |
| . | Any character (except /n newline) |
| | | Alternation. |
| {...} | Explicit quantifier notation. |
| [...] | Explicit set of characters to match. |
| (...) | Logical grouping of part of an expression. |
| * | 0 or more of previous expression. |
| + | 1 or more of previous expression. |
| ? | 0 or 1 of previous expression; also forces minimal matching when an expression might match several strings within a search string. |
| / | Preceding one of the above, it makes it a literal instead of a special character. Preceding a special matching character, see below. |
Metacharacter Examples | |
|---|---|
| Pattern | Sample Matches |
| ^abc | abc, abcdefg, abc123, ... |
| abc$ | abc, endsinabc, 123abc, ... |
| a.c | abc, aac, acc, adc, aec, ... |
| bill|ted | ted, bill |
| ab{2}c | abbc |
| a[bB]c | abc, aBc |
| (abc){2} | abcabc |
| ab*c | ac, abc, abbc, abbbc, ... |
| ab+c | abc, abbc, abbbc, ... |
| ab?c | ac, abc |
| a/sc | a c |
Character Escapes http://tinyurl.com/5wm3wl | |
|---|---|
| Escaped Char | Description |
| ordinary characters | Characters other than . $ ^ { [ ( | ) ] } * + ? / match themselves. |
| /a | Matches a bell (alarm) /u0007. |
| /b | Matches a backspace /u0008 if in a []; otherwise matches a word boundary (between /w and /W characters). |
| /t | Matches a tab /u0009. |
| /r | Matches a carriage return /u000D. |
| /v | Matches a vertical tab /u000B. |
| /f | Matches a form feed /u000C. |
| /n | Matches a new line /u000A. |
| /e | Matches an escape /u001B. |
| /040 | Matches an ASCII character as octal (up to three digits); numbers with no leading zero are backreferences if they have only one digit or if they correspond to a capturing group number. (For more information, see Backreferences.) For example, the character /040 represents a space. |
| /x20 | Matches an ASCII character using hexadecimal representation (exactly two digits). |
| /cC | Matches an ASCII control character; for example /cC is control-C. |
| /u0020 | Matches a Unicode character using a hexadecimal representation (exactly four digits). |
| /* | When followed by a character that is not recognized as an escaped character, matches that character. For example, /* is the same as /x2A. |
Character Classes http://tinyurl.com/5ck4ll | |
|---|---|
| Char Class | Description |
| . | Matches any character except /n. If modified by the Singleline option, a period character matches any character. For more information, see Regular Expression Options. |
| [aeiou] | Matches any single character included in the specified set of characters. |
| [^aeiou] | Matches any single character not in the specified set of characters. |
| [0-9a-fA-F] | Use of a hyphen ( 主站蜘蛛池模板： 华安县| 加查县| 晋江市| 罗平县| 马山县| 远安县| 东兴市| 静安区| 万年县| 曲阜市| 西吉县| 保定市| 盐山县| 兰溪市| 东宁县| 彭泽县| 蒙城县| 诸城市| 阿荣旗| 平江县| 瓦房店市| 兰考县| 阿克陶县| 大竹县| 衡东县| 塔城市| 烟台市| 驻马店市| 子长县| 高阳县| 庆城县| 青海省| 芮城县| 科技| 湘潭县| 常熟市| 揭阳市| 普格县| 雅江县| 灵武市| 彝良县| |