files/en-us/web/api/element/setattributenode/index.md
{{ APIRef("DOM") }}
The setAttributeNode() method of the {{domxref("Element")}} interface adds a new {{domxref("Attr")}} node to the specified element.
If you don't need to work with the attribute node (such as cloning from another element) before adding it, you can use the {{domxref("Element.setAttribute()", "setAttribute()")}} method instead.
setAttributeNode(attribute)
attribute
The replaced attribute node, if any, returned by this function.
This example copies the lang attribute from one element to another.
<div id="one" lang="en-US">one</div>
<div id="two">two</div>
const d1 = document.getElementById("one");
const d2 = document.getElementById("two");
const a = d1.getAttributeNode("lang");
d2.setAttributeNode(a.cloneNode(true));
// Returns: 'en-US'
console.log(d2.attributes[1].value);
If the attribute named already exists on the element, that attribute is replaced with the new one and the replaced one is returned.
{{Specifications}}
{{Compat}}