JavaScript "window.onload" – is "window" really necessary?

Question

I see people use "window.onload" all the time, but why? Isn't the "window" part completely superfluous?

Answer 1

window is an object with a property onload. Just setting the global variable onload doesn't mean anything.

Answer 2

If you don't, then the onload method will be attributed to the current object, whatever that is (if any). So sometimes it may work, but writing window.onload is the most explicit, specific and safe way to do it.

Answer 3

link text "The load event fires at the end of the document loading process. At this point, all of the objects in the document are in the DOM, and all the images and sub-frames have finished loading."

need to start working with the full DOM

Answer 4

Explanation: http://www.onlinetools.org/articles/unobtrusivejavascript/chapter4.html

Answer 5

<script type="text/javascript">    
    if(window.addEventListener){
        window.addhandler= function(who, which, what){
         return who.addEventListener(which, what, false);
        }
    }
    else if(window.attachEvent){
        window.addhandler= function(who, which, what){
         return who.addEventListener('on'+which, what);
        }
    }        
    function somefunction(){
        alert('page loaded')  
    }    
    addhandler(window,'load',somefunction);    
</script>