Javascript Regex Cheat Sheet
Basics
- . - Any character except newline
- a - The character a
- ab - The string ab
- a|b - a or b
- a\* - 0 or more a's
- \ - Escapes a special character
Quantifiers
- * - 0 or more
- + - 1 or more
- ? - 0 or 1
- {2} - Exactly 2
- {2,5} - Between 2 and 5
- {2,5} - Between 2 and 5
Groups
- (..) - Capturing group
- (?:..) - Non-capturing group
- \Y - Match the Y'th captured group
Character Classes
- [ab-d] - One character of a, b, c, d
- [^ab-d] - One character except a, b, c, d
- [\b] - Backspace character
- \d - One digit
- \D - One non-digit
- \s - One whitespace
- \S - One non-whitespace
- \w - One word character
- \w - One non-word character
Assertions
- ^ - Start of string
- $ - End of string
- \b - Word boundary
- \B - Non-word boundary
- (?=..) - Positive look ahead
- (?!..) - Negative look ahead
Flags
- g - Global match
- i - Ignore case
- m - ^ and $ match start and end of line
Special Characters
- \n - New line
- \r - Carriage return
- \t - Tab
- \0 - Null Character
- \YYY - Octal character YYY
- \xYY - Hexadecimal character YY
- \uYYYY - Hexadecimal character YYYY
- \cY - Control character Y
Replacement
- $$ - Insert $
- $& - Insert entire match
- $` - Insert preceding string
- $' - Insert following string
- $Y - Insert Y'th captured group
