| Character |
Description |
| \ |
Marks the next character as a special character, a literal, a
backreference, or an octal escape. For example, 'n' matches the character "n".
'\n' matches a newline character. The sequence '\\' matches "\" and "\("
matches "(". |
| ^ |
Matches the position at the beginning of the input string. If the RegExp
object's Multiline property is set, ^ also matches the position
following '\n' or '\r'. |
| $ |
Matches the position at the end of the input string. If the RegExp
object's Multiline property is set, $ also matches the position
preceding '\n' or '\r'. |
| * |
Matches the preceding character or subexpression zero or more
times. For example, zo* matches "z" and "zoo". * is equivalent to {0,}. |
| + |
Matches the preceding character or subexpression one or more times.
For example, 'zo+' matches "zo" and "zoo", but not "z". + is equivalent to
{1,}. |
| ? |
Matches the preceding character or subexpression zero or one time.
For example, "do(es)?" matches the "do" in "do" or "does". ? is equivalent to
{0,1} |
| {n} |
n is a nonnegative integer. Matches exactly n times.
For example, 'o{2}' does not match the 'o' in "Bob," but matches the two o's in
"food". |
| {n,} |
n is a nonnegative integer. Matches at least n times.
For example, 'o{2,}' does not match the "o" in "Bob" and matches all the o's in
"foooood". 'o{1,}' is equivalent to 'o+'. 'o{0,}' is equivalent to 'o*'. |
| {n,m} |
M and n are nonnegative integers, where n <=
m. Matches at least n and at most m times. For example,
"o{1,3}" matches the first three o's in "fooooood". 'o{0,1}' is equivalent to
'o?'. Note that you cannot put a space between the comma and the numbers. |
| ? |
When this character immediately follows any of the other
quantifiers (*, +, ?, {n}, {n,}, {n,m}), the
matching pattern is non-greedy. A non-greedy pattern matches as little of the
searched string as possible, whereas the default greedy pattern matches as much
of the searched string as possible. For example, in the string "oooo", 'o+?'
matches a single "o", while 'o+' matches all 'o's. |
| . |
Matches any single character except "\n". To match any character
including the '\n', use a pattern such as '[\s\S]'. |
| (pattern) |
A subexpression that matches pattern and captures the match.
The captured match can be retrieved from the resulting Matches collection using
the $0…$9 properties. To match parentheses characters ( ), use
'\(' or '\)'. |
| (?:pattern) |
A subexpression that matches pattern but does not capture
the match, that is, it is a non-capturing match that is not stored for possible
later use. This is useful for combining parts of a pattern with the "or"
character (|). For example, 'industr(?:y|ies) is a more economical expression
than 'industry|industries'. |
| (?=pattern) |
A subexpression that performs a positive lookahead search, which
matches the string at any point where a string matching pattern begins.
This is a non-capturing match, that is, the match is not captured for possible
later use. For example 'Windows (?=95|98|NT|2000)' matches "Windows" in
"Windows 2000" but not "Windows" in "Windows 3.1". Lookaheads do not consume
characters, that is, after a match occurs, the search for the next match begins
immediately following the last match, not after the characters that comprised
the lookahead. |
| (?!pattern) |
A subexpression that performs a negative lookahead search, which
matches the search string at any point where a string not matching pattern
begins. This is a non-capturing match, that is, the match is not captured for
possible later use. For example 'Windows (?!95|98|NT|2000)' matches "Windows"
in "Windows 3.1" but does not match "Windows" in "Windows 2000". Lookaheads do
not consume characters, that is, after a match occurs, the search for the next
match begins immediately following the last match, not after the characters
that comprised the lookahead. |
| x|y |
Matches either x or y. For example, 'z|food' matches
"z" or "food". '(z|f)ood' matches "zood" or "food".
|
| [xyz] |
A character set. Matches any one of the enclosed characters. For
example, '[abc]' matches the 'a' in "plain".
|
| [^xyz] |
A negative character set. Matches any character not enclosed. For
example, '[^abc]' matches the 'p' in "plain".
|
| [a-z] |
A range of characters. Matches any character in the specified
range. For example, '[a-z]' matches any lowercase alphabetic character in the
range 'a' through 'z'.
|
| [^a-z] |
A negative range characters. Matches any character not in the
specified range. For example, '[^a-z]' matches any character not in the range
'a' through 'z'.
|
| \b |
Matches a word boundary, that is, the position between a word and a
space. For example, 'er\b' matches the 'er' in "never" but not the 'er' in
"verb".
|
| \B |
Matches a nonword boundary. 'er\B' matches the 'er' in "verb" but
not the 'er' in "never".
|
| \cx |
Matches the control character indicated by x. For example,
\cM matches a Control-M or carriage return character. The value of x must
be in the range of A-Z or a-z. If not, c is assumed to be a literal 'c'
character.
|
| \d |
Matches a digit character. Equivalent to [0-9].
|
| \D |
Matches a nondigit character. Equivalent to [^0-9].
|
| \f |
Matches a form-feed character. Equivalent to \x0c and \cL. |
| \n |
Matches a newline character. Equivalent to \x0a and \cJ. |
| \r |
Matches a carriage return character. Equivalent to \x0d and \cM. |
| \s |
Matches any white space character including space, tab, form-feed,
and so on. Equivalent to [ \f\n\r\t\v]. |
| \S |
Matches any non-white space character. Equivalent to
[^ \f\n\r\t\v].
|
| \t |
Matches a tab character. Equivalent to \x09 and \cI. |
| \v |
Matches a vertical tab character. Equivalent to \x0b and \cK. |
| \w |
Matches any word character including underscore. Equivalent to
'[A-Za-z0-9_]'.
|
| \W |
Matches any nonword character. Equivalent to '[^A-Za-z0-9_]'.
|
| \xn |
Matches n, where n is a hexadecimal escape value.
Hexadecimal escape values must be exactly two digits long. For example, '\x41'
matches "A". '\x041' is equivalent to '\x04' & "1". Allows ASCII codes to
be used in regular expressions. |
| \num |
Matches num, where num is a positive integer. A
reference back to captured matches. For example, '(.)\1' matches two
consecutive identical characters.
|
| \n |
Identifies either an octal escape value or a backreference. If \n
is preceded by at least n captured subexpressions, n is a
backreference. Otherwise, n is an octal escape value if n is an
octal digit (0-7). |
| \nm |
Identifies either an octal escape value or a backreference. If \nm
is preceded by at least nm captured subexpressions, nm is a
backreference. If \nm is preceded by at least n captures, n
is a backreference followed by literal m. If neither of the preceding
conditions exists, \nm matches octal escape value nm when n
and m are octal digits (0-7). |
| \nml |
Matches octal escape value nml when n is an octal
digit (0-3) and m and l are octal digits (0-7). |
| \un |
Matches n, where n is a Unicode character expressed
as four hexadecimal digits. For example, \u00A9 matches the copyright symbol
(©). |
