Element.setAttributeNode()

setAttributeNode() adds a new Attr node to the specified element.

Syntax

var replacedAttr = element.setAttributeNode(attribute);

• attribute is the Attr node to set on the element.
• replacedAttr is the replaced attribute node, if any, returned by this function. 

Example

// <div id="one" align="left">one</div> 
// <div id="two">two</div> 
var d1 = document.getElementById("one"); 
var d2 = document.getElementById("two"); 
var a = d1.getAttributeNode("align"); 
d2.setAttributeNode(a.cloneNode(true)); 
alert(d2.attributes[1].value) 
// returns: `left'

Notes

If the attribute named already exists on the element, that attribute is replaced with the new one and the replaced one is returned.

This method is seldom used, with setAttribute() usually being used to change element's attributes.

DOM methods dealing with element's attributes:

Specification

DOM Level 2 Core: setAttributeNode (introduced in DOM Level 1 Core)