String.prototype.replace()
Returns a new string with the first match of a pattern replaced.
Syntax
str.replace(pattern, replacement)Parameters
| Name | Type | Required | Description |
|---|---|---|---|
pattern | string | RegExp | Yes | A substring or regular expression to match. A string matches only the first occurrence; a regex with the g flag matches all. |
replacement | string | Function | Yes | Replacement string (supports $1, $&, $`, etc.) or a function returning the replacement. |
Returns
string — A new string with the replacement applied.
Examples
console.log('a-b-c'.replace('-', '+'));
Output
a+b-c
console.log('a-b-c'.replace(/-/g, '+'));
Output
a+b+c
Notes
With a string pattern only the first occurrence is replaced - use a /g regex
or `replaceAll` for all. In the replacement string, `$$` inserts a literal `$`.
Does not mutate the original string.
Browser & runtime support
| Environment | Since version |
|---|---|
| chrome | 1.0 |
| firefox | 1.0 |
| safari | 1.0 |
| edge | 12 |
| node | 0.10 |