JavaScript RegExp \B Metacharacter
Example
Find the first occurrence of "LO", NOT at the beginning of a word:
let text = "HELLO, LOOK AT YOU!";
let pattern = /\BLO/;
Try it Yourself »
Definition and Usage
The \B metacharacter matches NOT at the beginning/end of a word.
Search for the pattern LO, not at the beginning of a word like this:
\BLO
Search for the pattern LO, not at the end of a word like this:
LO\B
Browser Support
/\B/ is an ECMAScript1 (ES1) feature.
ES1 (JavaScript 1997) is fully supported in all browsers:
| Chrome | Edge | Firefox | Safari | Opera | IE |
| Yes | Yes | Yes | Yes | Yes | Yes |
Syntax
new RegExp("\\Bregexp")
or simply:
/\Bregexp/
Syntax with modifiers
new RegExp("\\Bregexp", "g")
or simply:
/\Bregexp/g
More Examples
Example
Find the first occurrence of "LO", NOT at the END of a word:
let text = "HELLO, LOOK AT YOU";
let pattern = /LO\B/;
Try it Yourself »
Regular Expression Search Methods
In JavaScript, a regular expression text search, can be done with different methods.
With a pattern as a regular expression, these are the most common methods:
| Example | Description |
|---|---|
| text.match(pattern) | The String method match() |
| text.search(pattern) | The String method search() |
| pattern.exec(text) | The RexExp method exec() |
| pattern.test(text) | The RegExp method test() |
