type is radio or checkbox jquery code example

Example 1: 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!');
    }
  });
});

Example 2: jquery chek radio

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