jquery radio button checked or not code example

Example 1: if radio checked jquery

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

Example 2: jquery radio button checked event

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

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

Example 3: check radio button is checked jquery

$(document).ready(function(){
  $('#submit_button').click(function() {
    if (!$("input[name='name']:checked").val()) {
       alert('Nothing is checked!');
        return false;
    }
    else {
      alert('One of the radio buttons is checked!');
    }
  });
});