How jQuery to get the id of selected value from dropdown?

 on change event

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

Note: In dropdownlist if you want to set id,text relation from your database then, set id as value in option tag, not by adding extra id attribute inside option its not standard paractise though i did both in my answer but i prefer example 1

HTML Markup

Example 1:
    <select id="example1">
        <option value="1">one</option>
        <option value="2">two</option>
        <option value="3">three</option>
        <option value="4">four</option>
    </select>
Example 2 :
    <select id="example2">
        <option id="1">one</option>
        <option id="2">two</option>
        <option id="3">three</option>
        <option id="4">four</option>
    </select>

Jquery:

$("#example1").on('change', function () {
    alert($(this).val());
});

$("#example2").on('change', function () {
    alert($(this).find('option:selected').attr('id'));
});