RegExp
Character classes
| Pattern | Description |
|---|---|
. |
Any character, except newline |
\w |
Word |
\d |
Digit |
\s |
Whitespace |
\W |
Not word |
\D |
Not digit |
\S |
Not whitespace |
[abc] |
Any of a, b, or c |
[a-e] |
Characters between a and e
|
[1-9] |
Digit between 1 and 9
|
[[:print:]] |
Any printable character including spaces |
[^abc] |
Any character except a, b or c
|
Anchors
| Pattern | Description |
|---|---|
\G |
Start of match |
^ |
Start of string |
$ |
End of string |
\A |
Start of string |
\Z |
End of string |
\z |
Absolute end of string |
\b |
A word boundry |
\B |
Non-word boundry |
^abc |
Start with abc
|
abc$ |
End with abc
|
Escaped characters
| Pattern | Description |
|---|---|
\. \* \\ |
Escape special character used by regex |
\t |
Tab |
\n |
Newline |
\r |
Carriage return |
Groups
| Pattern | Description |
|---|---|
(abc) |
Capture group |
(a|b) |
Match a or b
|
(?:abc) |
Match abc, but don’t capture |
Quantifiers
| Pattern | Description |
|---|---|
a* |
Match 0 or more |
a+ |
Match 1 or more |
a? |
Match 0 or 1 |
a{5} |
Match exactly 5 |
a{,3} |
Match up to 3 |
a{3,} |
Match 3 or more |
a{1,3} |
Match between 1 and 3 |
Lookahead & Lookbehind
| Pattern | Description |
|---|---|
a(?=b) |
Match a in baby but not in bay
|
a(?!b) |
Match a in Stan but not in Stab
|
(?<=a)b |
Match b in crabs but not in cribs
|
(?<!a)b |
Match b in fib but not in fab
|