Copy class name in javascript

I need a way to copy the class name from one object to another.

For example

<div id="obj1" class"test"></div>
<div id="obj2"></div>

*run code*

<div id="obj1" class"test"></div>
<div id="obj2" class"test"></div>

I'm betting this is a pretty simple quest开发者_运维问答ion, but I'm relatively new to Javascript.

Any help is appreciated.

var obj1 = document.getElementById('obj1'),
    obj2 = document.getElementById('obj2');

obj2.className = obj1.className;

Just make sure this code does not run before the DOM is ready. A simple way to do this is to place this script just before the </body> tag.

document.getElementById("obj2").className = document.getElementById("obj1").className;

<script>
function changeIt(){
     document.getElementById('obj2').className = document.getElementById('obj1').className;

}
changeIt();
</script>

var obj1 = document.getElementById("obj1"),
    obj2 = document.getElementById("obj2");

obj2.className = obj1.className;

Or more generally:

function copyClassName(source, dest) {
    dest.className = source.className;
}

copyClassName(obj1, obj2);