in jQuery, how to get the quantity of an element based on id?

Question

I have a bunch of elements with <div id='id1'></div> and would like to return the quantity/count of them.

I am using the following code, but it always returns the value of 1:

alert( $('#id1').size() );

What am I doing wrong?

Answer 1

Note that there should only be one item with a particular identifier to begin with; what you're doing is considered invalid. jQuery rightfully stops after returning the first one it finds.

If you used class="foo" instead, you could use .size() correctly. For example, on this question's StackOverflow page:

>>> $('.votecell').size()
8

Answer 2

There should be only 1 item with any given id - if you need to tag multiple divs, you should use class. I suspect jQuery optimises for $('#id') and returns only the first, hence size always returns 1

Answer 3

If you want to have multiple divs with the same 'something' you need to use a class.

<div class='class1'></div>

alert( $('div.class1').size() );

Answer 4

While the ID should be unique, $("[id='id1']").length will get you what you want (In case you cannot change the HTML).

Answer 5

I figured out my own answer. I should have done:

alert( $('body #id1').length );

I just needed it to return a value greater than 1, and this does the trick.

I know I should be using class instead of id, but in my program, class is already used for something specific and I do another action based on the class which can't have multiple class names, but that's another story, and outside the scope of this topic. Thanks to everyone who chimed in though.