In the second version, you're passing the String returned from this.id
. Not the element itself.
So id.value
won't give you what you want.
You would need to pass the element with this
.
doSomething(this)
then:
function(el){
var value = el.value;
...
}
Note: In some browsers, the second one would work if you did:
window[id].value
because element IDs are a global property, but this is not safe.
It makes the most sense to just pass the element with this
instead of fetching it again with its ID.