Share ThisAdd Searching Tools with Regular Expression Operators in JavaScript
Part of the JavaScript & AJAX For Dummies Cheat Sheet
The regular expression mechanism adds extremely powerful searching tools to your programming. Here are some of the most commonly used regular expressions as they are used in JavaScript.
| Operator | Description | Sample pattern | matches | Doesn’t match |
| . (period) | Any single character except newline | . | E | \n |
| ^ | Beginning of string | ^a | apple | Banana |
| $ | End of string | a$ | banana | Apple |
| [characters] | Any of a list of characters in braces | [abcABC] | A | D |
| [char range] | Any character in the range | [a-zA-Z] | F | 9 |
| \d | Any single numerical digit | \d\d\d-\d\d\d\d | 123-4567 | The-thing |
| \b | A word boundary | \bthe\b | the | Theater |
| + | One or more occurrences of the previous character | \d+ | 1234 | Text |
| * | Zero or more occurrences of the previous character | [a-zA-Z]d* | B17, g | 7 |
| {digit} | Repeat preceding character digit times | \d{3}-\d{4} | 123-4567 | 999-99-9999 |
| {min, max} | Repeat preceding character at least min but not more than max times | .{2,4} | Ca, com, info | watermelon |
| (pattern segment) | Store results in pattern memory returned with code | ^(.).*\1$ | gig, wallow | Bobby |
