check radio button by id jquery code example

Example 1: jQuery check a radio button

// jQuery version 1.6 or above use:  
$("#myRadioID").prop("checked", true);
 
//jQuery versions below 1.6 use:
$("#myRadioID").attr('checked', 'checked');

Example 2: if radio checked jquery

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

Example 3: How can I know which radio button is selected via jQuery

if ($('input[name="radioName"]:checked', '#myForm').length) {
	//Yes, it's checked!
}

Example 4: jquery chek radio

//<input type="radio" name="book_condition" value="3" >
$("input:radio[value='3'][name='book_condition']").prop('checked',true);