addID in jQuery?

ID is an attribute, you can set it with the attr function:

$(element).attr('id', 'newID');

I'm not sure what you mean about adding IDs since an element can only have one identifier and this identifier must be unique.

I've used something like this before which addresses @scunliffes concern. It finds all instances of items with a class of (in this case .button), and assigns an ID and appends its index to the id name:

$(".button").attr('id', function (index) {
	return "button-" + index;
});

So let's say you have 3 items with the class name of .button on a page. The result would be adding a unique ID to all of them (in addition to their class of "button").

In this case, #button-0, #button-1, #button-2, respectively. This can come in very handy. Simply replace ".button" in the first line with whatever class you want to target, and replace "button" in the return statement with whatever you'd like your unique ID to be. Hope this helps!

do you mean a method?

$('div.foo').attr('id', 'foo123');

Just be careful that you don't set multiple elements to the same ID.

Like this :

var id = $('div.foo').attr('id');
$('div.foo').attr('id', id + ' id_adding');

1. get actual ID
2. put actuel ID and add the new one