Getting DOM element value using pure JavaScript
Update: The question was edited. Both of the solutions are now equivalent.
Original answer
Yes, most notably! I don't think the second one will work (and if it does, not very portably). The first one should be OK.
// HTML:<input id="theId" value="test" onclick="doSomething(this)" />// JavaScript:function(elem){ var value = elem.value; var id = elem.id; ...}This should also work.
The second function should have:
var value = document.getElementById(id).value;Then they are basically the same function.
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.