NamedNodeMap: setNamedItem() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The setNamedItem() method of the NamedNodeMap interface puts the Attr identified by its name in the map. If there is already an Attr with the same name in the map, it is replaced.

Syntax

js
setNamedItem(attr)

Parameters

attr

the attribute to insert in the map.

Return value

Returns the old attribute if replaced, or null if the attribute is new.

Exceptions

InUseAttributeError DOMException

Thrown if the attribute is still part of another map.

Example

html
<span class="foo" id="bar"></span>
<pre contenteditable></pre>
js
const span = document.querySelector("span");
const pre = document.querySelector("pre");

let result = `The \`<pre>\` element initially contains ${pre.attributes.length} attributes.\n\n`;

result += "We remove `class` from `<span>` and add it to `<pre>`.\n";
const classAttribute = span.attributes.removeNamedItem("class");
pre.attributes.setNamedItem(classAttribute);
result += `The \`<pre>\` element now contains ${pre.attributes.length} attributes.\n\n`;

result += "We get `id` from `<span>` and try to add it to `<pre>`.\n";
const id = span.attributes.getNamedItem("id");
try {
  pre.attributes.setNamedItem(id);
} catch (error) {
  result += `An exception has been raised: ${error.name}: ${error.message}.\n`;
}

pre.textContent = result;

Specifications

Specification
DOM
# dom-namednodemap-setnameditem

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
setNamedItem
Chrome – Full support
Chrome 1 (Release date: 2008-12-11)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 1 (Release date: 2004-11-09)
footnote Full support
Opera – Full support
Opera 12.1 (Release date: 2012-11-20)
footnote Full support
Safari – Full support
Safari 1 (Release date: 2003-06-23)
footnote Full support
Chrome Android – Full support
Chrome Android 18 (Release date: 2012-06-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 4 (Release date: 2011-03-29)
footnote Full support
Opera Android – Full support
Opera Android 12.1 (Release date: 2012-10-09)
footnote Full support
Safari on iOS – Full support
Safari on iOS 1 (Release date: 2007-06-29)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1 (Release date: 2013-04-27)
footnote Full support
WebView Android – Full support
WebView Android 4.4 (Release date: 2013-12-09)
footnote Full support
WebView on iOS – Full support
WebView on iOS 1 (Release date: 2007-06-29)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support