1var values=[];
2$('input[name="your-checkbox-name[]"]:checked').each(function () {
3  values[values.length] = (this.checked ? $(this).val() : "");
4});

1var selected = [];
2$('#checkboxes input:checked').each(function() {
3    selected.push($(this).attr('name'));
4});
5

1$('input:checkbox').prop('checked', true);

1<form id="form1" action="/controller/action" method="post">
2   <input type="checkbox" name="box1" class="cBox" />
3   <input type="checkbox" name="box2" class="cBox" />
4   <input type="checkbox" name="box3" class="cBox" />
5  <input type="submit" value="Submit" />
6</form>
7<script>
8$('#form1').submit(function() {
9   if ($('input:checkbox', this).length == $('input:checked', this).length ) {
10            // everything's fine...
11   } else {
12            alert('Please tick all checkboxes!');
13            return false;
14   }
15});
16</script>

1$('.theClass:checkbox:checked')

1$('#select_all').change(function() {
2  var checkboxes = $(this).closest('form').find(':checkbox');
3  checkboxes.prop('checked', $(this).is(':checked'));
4});