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

Note: This method is an alias of setNamedItem() you can use them interchangeably.

Syntax

js
setNamedItemNS(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 ob:one="one"></span>
<pre></pre>
js
const parser = new DOMParser();
// ob:one in <span> is not in a namespace, while ob:one in <warning>, is.
const xmlString =
  '<warning ob:one="test" xmlns:ob="http://www.example.com/ob">Beware!</warning>';
const doc = parser.parseFromString(xmlString, "application/xml");

const span = document.querySelector("span");
const pre = document.querySelector("pre");
const warning = doc.querySelector("warning");
const attrMap = span.attributes;

let result = `The '<span>' element initially contains ${attrMap.length} attribute.\n\n`;

result += "We remove `one` from '<span>' and adds it to '<pre>'.\n";
const one = warning.attributes.removeNamedItemNS(
  "http://www.example.com/ob",
  "one",
);
attrMap.setNamedItemNS(one);
result += `The '<span>' element now contains ${span.attributes.length} attributes:\n\n`;
result += "Prefix\tLocal name\tQualified name\n";
result += "=========================================\n";

for (const attr of attrMap) {
  result += `${attr.prefix}\t${attr.localName}\t\t${attr.name}\n`;
}

pre.textContent = result;

Specifications

Specification
DOM
# dom-namednodemap-setnameditemns

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
setNamedItemNS

Legend

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

Full support
Full support