Get selected value of a dropdown's item using jQuery

Question

How can I get the selected value of a dropdown box using jQuery?
I tried using

var value = $(\'#dropDownId\').val();

and

Answer 1

For Normal Page loaded dropdowns

  $("#dropDownId").on('change',function(){
     var value=$(this).val();
     alert(value);
  });

for dynamically added options Make sure to keep the id unique

  $(document).on('change','#dropDownId',function(){
    var value=$(this).val();
    alert(value)
  });