How to remove all options from a dropdown using jQuery / JavaScript

Anyone using JavaScript (as opposed to JQuery), might like to try this solution, where 'models' is the ID of the select field containing the list :-

var DDlist = document.getElementById("models");
while(DDlist.length>0){DDlist.remove(0);}

You can either use .remove() on option elements:

.remove() : Remove the set of matched elements from the DOM.

 $('#models option').remove(); or $('#models').remove('option');

or use .empty() on select:

.empty() : Remove all child nodes of the set of matched elements from the DOM.

 $('#models').empty();

however to repopulate deleted options, you need to store the option while deleting.

You can also achieve the same using show/hide:

$("#models option").hide();

and later on to show them:

$("#models option").show();

You didn't say on which event.Just use below on your event listener.Or in your page load

$('#models').empty()

Then to repopulate

$.getJSON('@Url.Action("YourAction","YourController")',function(data){
 var dropdown=$('#models');
dropdown.empty();  
$.each(data, function (index, item) {
    dropdown.append(
        $('<option>', {
            value: item.valueField,
            text: item.DisplayField
        }, '</option>'))
      }
     )});