Microsoft® JScript™ Regular Expression Syntax | Language Reference Version 3

See Also Applies To

##### Description

> Special characters and sequences are used in writing patterns for regular expressions. The following table describes these characters and includes short examples showing how the characters are used.

> Character | Description
> \ | Marks the next character as special. /n/ matches the character "n". The sequence /\n/ matches a linefeed or newline character.
> ^ | Matches the beginning of input or line.
> $ | Matches the end of input or line.
> * | Matches the preceding character zero or more times. /zo*/ matches either "z" or "zoo."
> + | Matches the preceding character one or more times. /zo+/ matches "zoo" but not "z."
> ? | Matches the preceding character zero or one time. /a?ve?/ matches the "ve" in "never."
> . | Matches any single character except a newline character.
> (pattern) | Matches pattern and remembers the match. The matched substring can be retrieved from the result Array object elements [1]...[n] or the RegExp object's $1...$9 properties. To match parentheses characters ( ), use "\(" or "\)".
> x|y | Matches either x or y. /z|food?/ matches "zoo" or "food."
> {n} | n is a nonnegative integer. Matches exactly n times. /o{2}/ does not match the "o" in "Bob," but matches the first two o's in "foooood."
> {n,} | n is a nonnegative integer. Matches at least n times. /o{2,}/ does not match the "o" in "Bob" and matches all the o's in "foooood." /o{1,}/ is equivalent to /o+/.
> {n,m} | m and n are nonnegative integers. Matches at least n and at most m times. /o{1,3}/ matches the first three o's in "fooooood."
> [xyz] | A character set. Matches any one of the enclosed characters. /[abc]/ matches the "a" in "plain."
> [^xyz] | A negative character set. Matches any character not enclosed. /[^abc]/ matches the "p" in "plain."
> \b | Matches a word boundary, such as a space. /ea*r\b/ matches the "er" in "never early."
> \B | Matches a nonword boundary. /ea*r\B/ matches the "ear" in "never early."
> \d | Matches a digit character. Equivalent to [0-9].
> \D | Matches a nondigit character. Equivalent to [^0-9].
> \f | Matches a form-feed character.
> \n | Matches a linefeed character.
> \r | Matches a carriage return character.
> \s | Matches any white space including space, tab, form-feed, and so on. Equivalent to [ \f\n\r\t\v]
> \S | Matches any nonwhite space character. Equivalent to [^ \f\n\r\t\v]
> \t | Matches a tab character.
> \v | Matches a vertical tab character.
> \w | Matches any word character including underscore. Equivalent to [A-Za-z0-9_].
> \W | Matches any nonword character. Equivalent to [^A-Za-z0-9_].
> \num | Matches num, where num is a positive integer. A reference back to remembered matches. \1 matches what is stored in RegExp.$1.
> /n/ | Matches n, where n is an octal, hexadecimal, or decimal escape value. Allows embedding of ASCII codes into regular expressions.

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