Metacharacter | Description |
---|---|
/ | Begins and ends the regular expression |
. | Matches any single character except the newline |
element* | Matches element zero or more times |
element+ | Matches element one or more times |
element? | Matches element zero or one time |
[characters] | Matches a character out of those contained within the brackets |
[^characters] | Matches a single character that is not contained within the brackets |
(regex) | Treats the regex as a group for counting or a following *, +, or ? |
left|right | Matches either left or right |
[l–r] | Matches a range of characters between l and r |
^ | Requires match to be at the string’s start |
$ | Requires match to be at the string’s end |
\b | Matches a word boundary |
\B | Matches where there is not a word boundary |
\d | Matches a single digit |
\D | Matches a single nondigit |
\n | Matches a newline character |
\s | Matches a whitespace character |
\S | Matches a nonwhitespace character |
\t | Matches a tab character |
\w | Matches a word character (a-z, A-Z, 0-9, and _) |
\W | Matches a nonword character (anything but a-z, A-Z, 0-9, and _) |
\x | x (useful if x is a metacharacter, but you really want x) |
{n} | Matches exactly n times |
{n,} | Matches n times or more |
{min,max} | Matches at least min and at most max times |
Regular Expression
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