Question

I want to get the id of the multiple selected check boxes

HTML:

<input type="checkbox" class="a" id="1">1
<input type="checkbox" class="a" id="2">2
<input type="checkbox" class="a" id="3">3
<input type="checkbox" class="a" id="4">4
<input type="checkbox" class="a" id="5">5

<input type="button" value="Button" id="button">

JS:

$("#button").live('click',function(){
    var a = document.getElementsByClassName("a");
    alert(a);
    alert(a.checked);
});

JS Fiddle

Answer 1

I’m not sure why everyone is posting code to check the boxes?

I want to get the id of the multiple selected check boxes

To do that, use this code:

$("#button").click(function() {
    var selected = $(".a:checked").map(function() {
        return this.id;
    }).get();
    alert(selected.join(","));
});

Example fiddle

You should also not use live(). delegate() or on() are the better solutions, but they are only required should the #button element be added to the page after page load.