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

replaceAll(regexp, newSubstr)
replaceAll(regexp, replacerFunction)

replaceAll(substr, newSubstr)
replaceAll(substr, replacerFunction)

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 replacerFunction. 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.

replacerFunction (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 returns a new string.

Specifying a string as a parameter

The replacement string can include the following special replacement patterns:

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 if the first argument of an replaceAll() invocation is a RegExp object or regular expression literal, the function will be invoked multiple times.

The arguments to the function are as follows:

(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

Browser compatibility

See also

• A polyfill of String.prototype.replaceAll is available in core-js
• String.prototype.replace()
• String.prototype.match()
• RegExp.prototype.exec()
• RegExp.prototype.test()