jquery selectors (finding tag)

I'开发者_如何学Cm sure this is simple, but I can't seem to figure it out. I need to be able to pass a function an element id, and know what element tag it is.

For example:

<a id="first"></a>
<input id="last" />

If I know the id is "first", how can I get that the tag is "a"?

This should do it:

var tagName = $("#first")[0].tagName;

The [0] is synonymous with get(0). You get the first element from the jQuery object and use the DOM tagName property. It's arguably more straightforward in vanilla Javascript:

var tagName = document.getElementById("first").tagName;

You can use the DOM property tagName like this:

document.getElementById('first').tagName

Or with jQuery, you would need to do:

$('#first')[0].tagName

I would use .nodeName here (there are a few reasons this matters), like this:

$("#first").get(0).nodeName
//or the vanilla js way...
document.getElementById("first").nodeName

$("#first").attr("tagName");