Regex cheat sheet
| Pattern | Matches |
|---|---|
. | Any character except a newline |
\d \w \s | Digit, word character (letter, digit, _), whitespace |
[abc] [^abc] [a-z] | One of a, b or c; anything but them; a range |
* + ? | 0 or more, 1 or more, 0 or 1 (add ? to make lazy) |
{2} {2,} {2,5} | Exactly 2, at least 2, between 2 and 5 |
^ $ \b | Start of text/line, end of text/line, word boundary |
(…) (?:…) (?<name>…) | Capture group, non-capturing group, named group |
a|b | a or b |
(?=…) (?!…) (?<=…) | Lookahead, negative lookahead, lookbehind |
Useful patterns
- Email address (simple):
[\w.+-]+@[\w-]+\.[\w.-]+ - URL:
https?:\/\/[^\s]+ - Date YYYY-MM-DD:
\d{4}-\d{2}-\d{2} - Hex color:
#(?:[0-9a-fA-F]{3}){1,2}\b - Extra spaces:
{2,}(replace with one space)
