RegEx
Character classes
| symbol | description |
|---|---|
. |
any character except newline |
\w \d \s |
word, digit, whitespace |
\W \D \S |
not word, digit, whitespace |
[abc] |
any of a, b, or c |
[^abc] |
not a, b, or c |
[a-g] |
character between a & g |
Anchors
| symbol | description |
|---|---|
^abc$ |
start / end of the string |
\b |
word boundary |
Escaped characters
| symbol | description |
|---|---|
\. \* \\ |
escaped special characters |
\t \n \r |
tab, linefeed, carriage return |
\u00A9 |
unicode escaped © |
Groups & Lookaround
| symbol | description |
|---|---|
(abc) |
capture group |
\1 |
backreference to group #1 |
(?:abc) |
non-capturing group |
(?=abc) |
positive lookahead |
(?!abc) |
negative lookahead |
Quantifiers & Alternation
| symbol | description |
|---|---|
a* a+ a? |
0 or more, 1 or more, 0 or 1 |
a{5} a{2,} |
exactly five, two or more |
a{1,3} |
between one & three |
a+? a{2,1}? |
match as few as possible |
ab ∣ cd |
match ab or cd |