radio button html checked jquery code example

Example 1: if radio checked jquery

$('#element').click(function() {
   if($('#radio_button').is(':checked')) { alert("it's checked"); }
});

Example 2: click on a radio button using jquery

$('input:radio[name=sex]:nth(0)').attr('checked',true);
or
$('input:radio[name=sex]')[0].checked = true;