String.prototype.replaceAll()

The replaceAll() method returns a new string with all matches of a pattern replaced by a replacement. The pattern can be a string or a RegExp, and the replacement can be a string or a function to be called for each match.

The original string is left unchanged.

Syntax

const newStr = str.replaceAll(regexp|substr, newSubstr|function)

when using a `regexp` you have to set the global ("g") flag; otherwise, it will throw a TypeError: "replaceAll must be called with a global RegExp".

Parameters

regexp (pattern)
A RegExp object or literal with the global flag. The matches are replaced with newSubstr or the value returned by the specified function. A RegExp without the global ("g") flag will throw a TypeError: "replaceAll must be called with a global RegExp".
substr
A String that is to be replaced by newSubstr. It is treated as a literal string and is not interpreted as a regular expression.
newSubstr (replacement)
The String that replaces the substring specified by the specified regexp or substr parameter. A number of special replacement patterns are supported; see the "Specifying a string as a parameter" section below.
function (replacement)
A function to be invoked to create the new substring to be used to replace the matches to the given regexp or substr. The arguments supplied to this function are described in the "Specifying a function as a parameter" section below.

Return value

A new string, with all matches of a pattern replaced by a replacement.

Description

This method does not change the calling String object. It simply returns a new string.

Specifying a string as a parameter

The replacement string can include the following special replacement patterns:

Pattern Inserts
$$ Inserts a "$".
$& Inserts the matched substring.
$` Inserts the portion of the string that precedes the matched substring.
$' Inserts the portion of the string that follows the matched substring.
$n Where n is a positive integer less than 100, inserts the nth parenthesized submatch string, provided the first argument was a RegExp object. Note that this is 1-indexed.

Specifying a function as a parameter

You can specify a function as the second parameter. In this case, the function will be invoked after the match has been performed. The function's result (return value) will be used as the replacement string. (Note: The above-mentioned special replacement patterns do not apply in this case.)

Note that the function will be invoked multiple times for each full match to be replaced if the regular expression in the first parameter is global.

The arguments to the function are as follows:

Possible name Supplied value
match The matched substring. (Corresponds to $& above.)
p1, p2, ... The nth string found by a parenthesized capture group, provided the first argument to replace() was a RegExp object. (Corresponds to $1, $2, etc. above.) For example, if /(\a+)(\b+)/, was given, p1 is the match for \a+, and p2 for \b+.
offset The offset of the matched substring within the whole string being examined. (For example, if the whole string was 'abcd', and the matched substring was 'bc', then this argument will be 1.)
string The whole string being examined.

(The exact number of arguments depends on whether the first argument is a RegExp object—and, if so, how many parenthesized submatches it specifies.)

Examples

Using replaceAll

'aabbcc'.replaceAll('b', '.'); 
// 'aa..cc'

Non-global regex throws

When using a regular expression search value, it must be global. This won't work:

'aabbcc'.replaceAll(/b/, '.');
TypeError: replaceAll must be called with a global RegExp

This will work:

'aabbcc'.replaceAll(/b/g, '.');
"aa..cc"

Specifications

Specification
ECMAScript (ECMA-262)
The definition of 'String.prototype.replaceAll' in that specification.

Browser compatibility

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DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
replaceAllChrome Full support 85Edge Full support 85Firefox Full support 77IE No support NoOpera Full support 71Safari Full support 13.1WebView Android Full support 85Chrome Android Full support 85Firefox Android Full support 79Opera Android Full support 60Safari iOS Full support 13.4Samsung Internet Android No support Nonodejs No support No

Legend

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See also