JavaScript RegExp Patterns
RexExp Flags
Revised July 2025
| Flag | Description |
|---|---|
| /d | Performs substring matches (new in 2022) |
| /g | Performs a global match (find all) |
| /i | Performs case-insensitive matching |
| /m | Performs multiline matching |
| /s | Allows . (dot) to match line terminator characters (new in 2018) |
| /u | Enables Unicode support (new in 2015) |
| /v | An upgrade to the /u flag for better Unicode support (new in 2025) |
| /y | Performs a "sticky" search (new in 2015) |
RexExp Character Classes
| [] | Description |
|---|---|
| [a] | Matches the character between the brackets |
| [^a] | Matches characters different from the character between the brackets |
| [abc] | Matches any of the characters between the brackets |
| [^abc] | Mathes any character NOT between the brackets |
| [A-Z] | Matches character in the range from A to Z |
| [^A-Z] | Matches characters NOT in the range from A to Z |
| [0-9] | Matches characters in the range from 0 to 9 |
| [^0-9] | Mathis characters NOT in the range from 0 to 9 |
| (x|y) | Matches the x or y alternatives specified |
RexExp Metacharacters
| Char | Description |
|---|---|
| ^ | Matches from beginning of a string, or the beginning of a line if the m (multiline) flag is set |
| $ | Matches from the end of a string, or the end of a line if the m (multiline) flag is set |
| . | Matches single (wildcard) characters, except line terminators like \n and \r |
| \w | Matches word characters (alphanumeric and underscore _) |
| \W | Matches non-word characters |
| \d | Matches digits (0-9) |
| \D | Matches non-digit characters |
| \s | Matches whitespace characters like space, tab \t, and newline \n |
| \S | Matches non-whitespace character |
| \b | Matches from the beginning or end of a word |
| \B | Matches not from the beginning or end of a word |
| [\b] | Matches backspace characters |
| \0 | Matches NULL characters |
| \n | Matches new line characters |
| \f | Matches form feed characters |
| \r | Matches carriage returns characters |
| \t | Matches tab characters |
| \v | Matches vertical tab characters |
| \p{} | Matches characters based on a given Unicode Property (new 2018) |
| \P{} | Matches character NOT based on a given Unicode Property (new 2018) |
| \ddd | Matches characters specified by an octal number ddd |
| \xhh | Matches characters specified by a hexadecimal number hh |
| \uhhhh | Matches Unicode character specified by a hexadecimal number hhhh |
RexExp Quantifiers
| Quant | Description |
|---|---|
| n+ | Matches strings that contains at least one n |
| n* | Matches strings that contains zero or more occurrences of n |
| n? | Matches strings that contains zero or one occurrences of n |
| n{X} | Matches strings that contains a sequence of X n's |
| n{X,Y} | Matches strings that contains a sequence of X to Y n's |
| n{X,} | Matches strings that contains a sequence of at least X n's |
| n$ | Matches strings with n at the end of it |
| ^n | Matches strings with n at the beginning of it |
| ?=n | Matches strings that is followed by a specific string n |
| ?!n | Matches strings that is not followed by a specific string n |
