JavaScript - This
Saturday, June 5th, 2010 | Uncategorized
One of the most powerful JavaScript keywords is this.
http://www.quirksmode.org/js/this.html
element.onclick = doSomething;
The function is copied in its entirety to the onclick property (which now becomes a method). So if the event handler is executed this refers to the HTML element.
However, if you use inline event registration
<element onclick=”doSomething()”>
you do not copy the function! Instead, you refer to it, and the difference is crucial.
Examples:
element.onclick = doSomething
element.addEventListener(’click’,doSomething,false)<element onclick=”doSomething(this)”>
function doSomething(obj) {
obj.style.color = ‘#cc0000′;
}
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