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- Blue shaded to match the text, syntax parsing, highly recommended
- Your regular expression is expressed as a graphics state machine
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- Easy to learn regular expressions (geeks College reproduced in other people's) (see syntax available)
- Regular Expressions 30 minutes Start Tutorial
To learn righteousness
- Constant practice (which is the core around regular practice to learn the most effective)
- One must be thinking about how to achieve their own, rather than rationality would like to see the answer
- There is a demand can realize their regular engine
Exercise
Wait filled pit
grammar
| character | description |
|---|---|
| \ | The next character is marked as a special character, or a literal character, or a backward reference, or an octal escape. For example, " n" matches the character n" ." " \n" Matches a newline. Serial " \\," matching " \" and " \(" the match (" ." |
| ^ | Matches the beginning of the string. If the object is set RegExp Multiline property, ^ also matches " \n" or " \rposition" after. |
| $ | Matches the input end of the string. If the RegExp object's Multiline property is set, $ also matches " \n" or " \rposition before." |
| * | Matches the preceding subexpression zero or more times. For example, zo * matches " z" and zoo" ." * Is equivalent to {0}. |
| + | Matches the preceding subexpression one or more times. For example, " zo+" can match " zo" and zoo" ", but can not match z" ." + Is equivalent to {1}. |
| ? | Matches the preceding subexpression zero or one. For example, " do(es)?" matches " does" or " does" in do" ." ? Is equivalent to {0,1}. |
| {n} | n is a nonnegative integer. Matching the determined n times. For example, " o{2}" does not match the " Bob" in o" ", but can match the " food" in the two o. |
| {n,} | n is a nonnegative integer. Matching at least n times. For example, " o{2,}" does not match the " Bob" in o" ", but it can match " fooooodall o" in. " o{1,}" Is equivalent to o+" ." " o{0,}" Is equivalent to o*" ." |
| {n,m} | m and n are non-negative integers, where n <= m. Match at least n times and match up to m times. For example, " o{1,3}" will match " fooooood" in the first three o. " o{0,1}" Is equivalent to o?" ." Please note that no spaces between the comma and the two numbers. |
| ? | When the character immediately to any other qualifier (*, +,?, { N}, {n,}, {n, m}) when the rear, non-greedy matching pattern. Non-greedy pattern matches as little as possible the search string, and the default greedy pattern matches as much of the string search. For example, the string oooo" ", " o+?" will match a single o" " and " o+" matches all the o" ." |
| . | In addition to matching " \``nany single character other than" in. To match including " \``n" any characters, including use as " (.|\n)" model. |
| (pattern) | Match the pattern and get the match. The matching can be obtained from the Matches have been used in collection SubMatches VBScript, JScript is used in the $ 0 ... $ 9 properties. To match parentheses characters, use " \(" or \)" ." |
| (?:pattern) | But not to acquire matching pattern matching results, that this is a non-access match, not stored for later use. This "use or character (|)" to a combination of the various parts of the model is useful. For example, " industr(?:y|ies)" it is more than a ' industry|industries' more brief expressions. |
| (?=pattern) | Forward definitely pre-investigation, matching the search string at the beginning of the string any pattern matching. This is a non-access match, that is, the match does not need to obtain for later use. For example, " Windows(?=95|98|NT|2000)" matches " Windows2000" in Windows" ", but not " Windows3.1" the Windows" ." Pre-check does not consume characters, that is, after a match occurs, the last match after the next match to start the search immediately, rather than starting from the characters that contains pre-investigation. |
| (?!pattern) | Forward negative pre-investigation, matching the search string at the beginning of any match pattern string. This is a non-access match, that is, the match does not need to obtain for later use. For example " Windows(?!95|98|NT|2000)" matches " Windows3.1" in Windows" ", but not " Windows2000" the Windows" ." Pre-check does not consume characters, that is, after a match occurs, after the last match started immediately next match search, rather than starting from the characters that contains pre-investigation |
| (?<=pattern) | Reverse certainly pre-investigation, and certainly pre-investigation Quasi forward, but in the opposite direction. For example, " (?<=95|98|NT|2000)Windows" matches " 2000Windows" in Windows" ", but not " 3.1Windows" the Windows" ." |
| (?<!pattern) | Reverse negative pre-check, with a negative pre-investigation Quasi forward, but in the opposite direction. For example " (?<!95|98|NT|2000)Windows" matches " 3.1Windows" in Windows" ", but not " 2000Windows" the Windows" ." |
| x | and | Match x or y. For example, " z|food" matches " z" or food" ." " (z|f)ood" The match " zood" or food" ." |
| [xyz] | Set of characters. Matches any character included. For example, " [abc]" matches " plain" in a" ." |
| [^xyz] | Negative character sets. Matches any character not included. For example, " [^abc]" matches " plain" in p" ." |
| [a-z] | Range of characters. Matches any character within the specified range. For example, " [a-z]" matches " a" to " z" any lowercase characters in the range. |
| [^a-z] | Negative character range. Matches any character not in any specified range. For example, " [^a-z]" may not match any " a" to " z" Any range. |
| \b | Matches a word boundary, that is, it refers to the location and spaces between words. For example, " er\b" matches " never" in er" ", but not " verb" the er" ." |
| \B | 匹配非单词边界。“er\B”能匹配“verb”中的“er”，但不能匹配“never”中的“er”。 |
| \cx | 匹配由x指明的控制字符。例如，\cM匹配一个Control-M或回车符。x的值必须为A-Z或a-z之一。否则，将c视为一个原义的“c”字符。 |
| \d | 匹配一个数字字符。等价于[0-9]。 |
| \D | 匹配一个非数字字符。等价于[^0-9]。 |
| \f | 匹配一个换页符。等价于\x0c和\cL。 |
| \n | 匹配一个换行符。等价于\x0a和\cJ。 |
| \r | 匹配一个回车符。等价于\x0d和\cM。 |
| \s | 匹配任何空白字符，包括空格、制表符、换页符等等。等价于[ \f\n\r\t\v]。 |
| \S | 匹配任何非空白字符。等价于[^ \f\n\r\t\v]。 |
| \t | 匹配一个制表符。等价于\x09和\cI。 |
| \v | 匹配一个垂直制表符。等价于\x0b和\cK。 |
| \w | 匹配包括下划线的任何单词字符。等价于“[A-Za-z0-9_]”。 |
| \W | 匹配任何非单词字符。等价于“[^A-Za-z0-9_]”。 |
| \xn | 匹配n，其中n为十六进制转义值。十六进制转义值必须为确定的两个数字长。例如，“\x41”匹配“A”。“\x041”则等价于“\x04&1”。正则表达式中可以使用ASCII编码。. |
| \num | 匹配num，其中num是一个正整数。对所获取的匹配的引用。例如，“(.)\1”匹配两个连续的相同字符。 |
| \n | 标识一个八进制转义值或一个向后引用。如果\n之前至少n个获取的子表达式，则n为向后引用。否则，如果n为八进制数字（0-7），则n为一个八进制转义值。 |
| \nm | 标识一个八进制转义值或一个向后引用。如果\nm之前至少有nm个获得子表达式，则nm为向后引用。如果\nm之前至少有n个获取，则n为一个后跟文字m的向后引用。如果前面的条件都不满足，若n和m均为八进制数字（0-7），则\nm将匹配八进制转义值nm。 |
| \nml | 如果n为八进制数字（0-3），且m和l均为八进制数字（0-7），则匹配八进制转义值nml。 |
| \un | 匹配n，其中n是一个用四个十六进制数字表示的Unicode字符。例如，\u00A9匹配版权符号（©）。 |