how to check selected radio button in 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: jquery chek radio

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