How do I clear the dropdownlist values on button click event using jQuery?
$('#dropdownid').empty();
That will remove all <option>
elements underneath the dropdown element.
If you want to unselect selected items, go with the code from Russ.
A shorter alternative to the first solution given by Russ Cam would be:
$('#mySelect').val('');
This assumes you want to retain the list, but make it so that no option is selected.
If you wish to select a particular default value, just pass that value instead of an empty string.
$('#mySelect').val('someDefaultValue');
or to do it by the index of the option, you could do:
$('#mySelect option:eq(0)').attr('selected','selected'); // Select first option