Regular Expressions
JavaScript 1.2 supports regular expressions, using the same syntax as
Perl 4. A regular expression is specified literally as a sequence of
characters within forward slashes (/), or as a JavaScript string
passed to the RegExp() constructor. The optional g (global search)
and i (case-insensitive search) modifiers may follow the second /
character, or may be passed to RegExp().
The following table summarizes regular expression syntax:
| Character | Meaning |
|---|---|
\n, \r, \t
|
Match literal newline, carriage return, tab |
\, \/, \*, \+, \?, etc. |
Match a special character literally, ignoring or escaping its special meaning |
[ . . . ]
|
Match any one character between brackets |
[^ . . . ]
|
Match any one character not between brackets |
.
|
Match any character other than newline |
\w, \W
|
Match any word/nonword character |
\s, \S
|
Match any whitespace/nonwhitespace |
\d, \D
| Match any digit/nondigit |
^, $
|
Require match at beginning/end of a string, or in multiline mode, beginning/end of a line |
\b, \B
|
Require match at a word boundary nonboundary |
?
|
Optional term; match zero or one time |
+
|
Match previous term one or more times |
*
|
Match term zero or more times |
{
n
}
|
Match previous term exactly n times |
{
n,}
|
Match previous term n or more times |
{
n,m
}
|
Match at least n but no more than m times |
a
|
b
| Match either a or b |
(
sub
)
|
Group subexpression sub into a single term, and remember the text that it matched |
n
|
Match exactly the same characters that were matched by subexpression ... |
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