gaskell.org

This one comes up quite often on the Stack Overflow, so I’ll give my shot at answering.

If you have a single checkbox that you’d like to check I like this style:

    if($('#your_checkbox_id').is(':checked')) {
      alert('checked!');
    } else {
      alert('not checked!');
    }

Here’s another way of determining of a checkbox is checked:

    if($('#your_checkbox_id:checked').length) {
      alert('checked!');
    } else {
      alert('not checked!');
    }

Here’s more jQuery checkbox selector goodness.

This selector will get all of the checkboxes (checked or unchecked) in the DOM:

    $(':checkbox');

All of the checked checkboxes:

    $(':checkbox:checked');

All of the unchecked checkboxes:

    $(':checkbox').not(':checked');

Here’s all of the checkboxes within a form:

    $('form :checkbox');

How to check all checkboxes:

    $(':checkbox').attr('checked', 'checked');

Unchecking all checkboxes:

    $(':checkbox').removeAttr('checked');