files/en-us/web/api/namednodemap/setnameditem/index.md
{{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.
setNamedItem(attr)
attr
Returns the old attribute if replaced, or null if the attribute is new.
InUseAttributeError {{domxref("DOMException")}}
<span class="foo" id="bar"></span>
<pre contenteditable></pre>
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;
{{EmbedLiveSample("Example", "100%", 160)}}
{{Specifications}}
{{Compat}}