NamedNodeMap: setNamedItem() method

{{APIRef("DOM")}} 

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

Syntax

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 {{domxref("DOMException")}} 
  • : Thrown if the attribute is still part of another map.

Example

<span one="one" two="two"></span>
<pre test="testValue"></pre>

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

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

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

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

pre.textContent = result;

{{EmbedLiveSample("Example", "100%", 160)}} 

Specifications

{{Specifications}} 

Browser compatibility

{{Compat}}