if checkbox is checked by jQuery, 'checked' attribute won't disappear when unchecking it manually

[schmidt.ajax@…]

The following code makes checkbox unable to correctly determine whether checkbox checked or not:

<script src='jquery-1.6.4.min.js'></script>
<script>
$(window).load(function() {
  $('#chk').attr('checked', 'checked');
  $('#test').click(function(e) {
	alert($('#chk').attr('checked'));
  });
});
</script>

<input id='chk' type='checkbox'>BadCheckbox
<button id='test'>Uncheck & press it to see</button>

So, after clicking on checkbox it will be unchecked, but 'checked' attribute will stay on it.

[dmethvin]

That is correct behavior. The user's click does not remove the attribute from the HTML. It only changes the property. If you want to know the dynamic state, use .prop("checked") instead.