Regular Pattern
Character | Description |
---|---|
\ |
Marks the next character as either a special character
or a literal. For example, "n" matches the character "n". "\n" matches
a newline character. The sequence "\\" matches "\" and "\(" matches "(".
|
^ |
Matches the beginning of input.
|
$ |
Matches the end of input.
|
* |
Matches the preceding character zero or more times. For
example, "zo*" matches either "z" or "zoo".
|
+ |
Matches the preceding character one or more times. For
example, "zo+" matches "zoo" but not "z".
|
? |
Matches the preceding character zero or one time. For
example, "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 resulting Matches collection,
using Item [0]...[n]. To match parentheses characters ( ), use
"\(" or "\)".
|
x|y |
Matches either x or y. For example, "z|wood"
matches "z" or "wood". "(z|w)oo" matches "zoo" or "wood".
|
{n} |
n is a nonnegative integer. Matches exactly n
times. For example, "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. 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. 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?".
|
[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".
|
[^m-z] |
A negative range characters. Matches any character not
in the specified range. For example, "[m-z]" matches any character not
in the range "m" 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 non-word boundary. "ea*r\B" matches the "ear"
in "never early".
|
\d |
Matches a digit character. Equivalent to [0-9].
|
\D |
Matches a non-digit character. Equivalent to [^0-9].
|
\f |
Matches a form-feed character.
|
\n |
Matches a newline character.
|
\r |
Matches a carriage return character.
|
\s |
Matches any white space including space, tab, form-feed,
etc. 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 non-word character. Equivalent to "[^A-Za-z0-9_]".
|
\num |
Matches num, where num is a positive integer.
A reference back to remembered matches. For example, "(.)\1" matches two
consecutive identical characters.
|
\n |
Matches n, where n is an octal escape value.
Octal escape values must be 1, 2, or 3 digits long. For example, "\11"
and "\011" both match a tab character. "\0011" is the equivalent of "\001"
& "1". Octal escape values must not exceed 256. If they do, only the
first two digits comprise the expression. Allows ASCII codes to be used
in regular expressions.
|
\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.
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