Why can't I get the ID of this button using jQuery?

Question

jsFiddle

I'm trying the get the ID of a button using $(this).id, but it's coming up as undefined. What am I doing wrong? Thanks for reading.

EDIT: Code from jsFiddle example:

HTML

<button id='remove_button' type='button'>Remove</button>​

jQuery

$('#remove_button').mouseup(function(){
     alert($(this).id);
});​

Answer 1

$(this).attr('id');

:D

EDIT

although my answer is correct, the better way to do it is like dana said. So, you should accept dana answer instead of mine.

Answer 2

$(this)

Gives you a reference to a jQuery object. You can either use the attr() function like Mario says, or even just do this:

this.id

Answer 3

You can use either:

this.id // <== more efficient and faster

or

$(this).attr("id")

this is a DOM element, as you can see on this MDC reference page you can use the id property of a DOM element to set or get that element's id.

You can create a jQuery object out of this by wrapping it like so: $(this). $(this) is not a DOM element, so it doesn't have the id property. Instead, you can use the .attr() jQuery method to get the id of the DOM element that is being represented by the jQuery object $(this).

Whenever you can use native DOM properties directly, it is faster than using jQuery methods, so this.id is more efficient than $(this).attr("id").

jsFiddle example