Web/API/DOMTokenList/replace

The replace() method of the DOMTokenList interface replaces an existing token with a new token. If the first token doesn't exist, replace() returns false immediately, without adding the new token to the token list.

Syntax

tokenList.replace(oldToken, newToken);

Parameters

oldToken

A DOMString representing the token you want to replace.

newToken

A DOMString representing the token you want to replace oldToken with.

Return value

A boolean value, which is true if oldToken was successfully replaced, or false if not.

Note: In older browsers, replace() returns void.

Examples

In the following example we retrieve the list of classes set on a <span> element as a DOMTokenList using Element.classList. We then replace a token in the list, and write the list into the <span>'s Node.textContent.

First, the HTML:

<span class="a b c"></span>

Now the JavaScript:

let span = document.querySelector("span");
let classes = span.classList;

let result = classes.replace("c", "z");
console.log(result);

if (result) {
  span.textContent = classes;
} else {
  span.textContent = 'token not replaced successfully';
}

The output looks like this:

Polyfill

The following polyfill will add the replace method to the DOMTokenList class.  The following code will only work with IE10-11. To use with earlier versions of IE, refer to the polyfill at element.classList#Polyfill

DOMTokenList.prototype.replace = function (a, b) {
    if (this.contains(a)) {
        this.add(b);
        this.remove(a);
        return true;
    }
    return false;
}

Specifications

Specification	Status	Comment
DOMThe definition of 'replace()' in that specification.	Living Standard	Initial definition

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
replace	Chrome Full support 61	Edge Full support 17	Firefox Full support 49	IE No support No	Opera Full support 48	Safari Full support 10.1	WebView Android Full support 61	Chrome Android Full support 61	Firefox Android Full support 49	Opera Android Full support 45	Safari iOS Full support 10.3	Samsung Internet Android Full support 8.0
return()'s value is a boolean, not void as it used to be.	Chrome Full support 67	Edge Full support 18	Firefox Full support 61	IE No support No	Opera Full support 54	Safari Full support 12	WebView Android Full support 67	Chrome Android Full support 67	Firefox Android Full support 61	Opera Android Full support 48	Safari iOS Full support 12	Samsung Internet Android Full support 9.0

Legend

Full support  

Full support

No support  

No support

DOMTokenList.replace() by Mozilla Contributors is licensed under CC-BY-SA 2.5.