Answer by BlackPanther for Check if checkbox is checked with jQuery

Actually, according to jsperf.com, The DOM operations are fastest, then $().prop() followed by $().is()!!

Here are the syntaxes :

var checkbox = $('#'+id);
/* OR var checkbox = $("input[name=checkbox1]"); whichever is best */

/* The DOM way - The fastest */
if(checkbox[0].checked == true)
   alert('Checkbox is checked!!');

/* Using jQuery .prop() - The second fastest */
if(checkbox.prop('checked') == true)
   alert('Checkbox is checked!!');

/* Using jQuery .is() - The slowest in the lot */
if(checkbox.is(':checked') == true)
   alert('Checkbox is checked!!');

I personally prefer .prop(). Unlike .is(), It can also be used to set the value.