check radio button checked or not jquery code example

Example 1: if radio checked jquery

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

Example 2: radio button checked event jquery

$('#radio-button-id').click(function() {
  if($('#radio-button-id').is(':checked')) 
  { 
    //input where you put a value
    $('#program').val("radio-button-text");
  }                      
});

Example 3: jquery radio button checked event

$('input:radio[name="postage"]').change(function(){

        if ($(this).val() == 'Yes') {
            //true
        }
        else {
            //false
        }
    });

Example 4: jquery chek radio

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