How do I clear all options in a dropdown box?

My code works in IE but breaks in Safari, Firefox, and Opera. (big surprise)

document.getElementById("DropList").options.length=0;

After searching, I've learned that it's the length=0 that it doesn't like.
I've tried ...options=null and var clear=0; ...length=clear with the same result.

I am doing this to multiple objects at a time, so I am looking for some lightweight JS code.

To remove the options of an HTML element of select, you can utilize the remove() method:

function removeOptions(selectElement) {
   var i, L = selectElement.options.length - 1;
   for(i = L; i >= 0; i--) {
      selectElement.remove(i);
   }
}

// using the function:
removeOptions(document.getElementById('DropList'));

It's important to remove the options backwards; as the remove() method rearranges the options collection. This way, it's guaranteed that the element to be removed still exists!

If you wish to have a lightweight script, then go for jQuery. In jQuery, the solution for removing all options will be like:

$("#droplist").empty();

Probably, not the cleanest solution, but it is definitely simpler than removing one-by-one:

document.getElementById("DropList").innerHTML = "";

This is the best way :

function (comboBox) {
    while (comboBox.options.length > 0) {                
        comboBox.remove(0);
    }        
}

You can use the following to clear all the elements.

var select = document.getElementById("DropList");
var length = select.options.length;
for (i = length-1; i >= 0; i--) {
  select.options[i] = null;
}

This is a short way:

document.getElementById('mySelect').innerText = null;

One line, no for, no JQuery, simple.

I'd like to point out that the problem in the original question is not relevant today anymore. And there is even shorter version of that solution:

selectElement.length = 0;

I've tested that both versions work in Firefox 52, Chrome 49, Opera 36, Safari 5.1, IE 11, Edge 18, latest versions of Chrome, Firefox, Samsung Internet and UC Browser on Android, Safari on iPhone 6S, Android 4.2.2 stock browser. I think it is safe to conclude that it's absolutely compatible with whatever device there is right now, so I recommend this approach.

This is a bit modern and pure JavaScript

document.querySelectorAll('#selectId option').forEach(option => option.remove())

function removeOptions(obj) {
    while (obj.options.length) {
	    obj.remove(0);
    }
}

Try

document.getElementsByTagName("Option").length=0

Or maybe look into the removeChild() function.

Or if you use jQuery framework.

$("DropList Option").each(function(){$(this).remove();});

with PrototypeJS :

$('yourSelect').select('option').invoke('remove');

Note that a select can have both

• optgroup &
• options collection
  as its children.

So,

Method #1

var selectElement = document.getElementById('myselectid');
selectElement.innerHTML = '';

Method #2

var selectElement = document.getElementById('myselectid');
selectElement.textContent = '';

I tested, both work on Chrome.
I like the simpler, the old fashioned, method #1.

If you are using JQuery and your select control has ID "DropList" you can remove its options doing this way:

$('#DropList option').remove();

Actually it works for me with any option list, like datalist.

Hope it helps.

Using JQuery is a prettier, shorter & smarter way to do it!

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

For Vanilla JavaScript there is simple and elegant way to do this:

for(var o of document.querySelectorAll('#DropList > option')) {
  o.remove()
}

Go reverse. Reason is size decreases after each remove.

for (i = (len-1); i > -1; i--) {
	document.getElementById("elementId").remove(i);
}

I think that is the best sol. is

 $("#myselectid").html(''); 

This can be used to clear options:

function clearDropDown(){
  var select = document.getElementById("DropList"),
      length = select.options.length;
  while(length--){
    select.remove(length);
  }
}

<select id="DropList" >
  <option>option_1</option>
  <option>option_2</option>
  <option>option_3</option>
  <option>option_4</option>
  <option>option_5</option>
</select>
<button onclick="clearDropDown()">clear list</button>

var select = document.getElementById("DropList");
var length = select.options.length;
for (i = 0; i < length; i++) {
  select.options[i].remove();
}

Hope, this code will helps you

var select = document.getElementById('/*id attribute of your select here*/');
for (var option in select){
    select.remove(option);
}

The items should be removed in reverse, otherwise it will cause an error. Also, I do not recommended simply setting the values to null, as that may cause unexpected behaviour.

var select = document.getElementById("myselect");
for (var i = select.options.length - 1 ; i >= 0 ; i--)
    select.remove(i);

Or if you prefer, you can make it a function:

function clearOptions(id)
{
    var select = document.getElementById(id);
    for (var i = select.options.length - 1 ; i >= 0 ; i--)
        select.remove(i);
}
clearOptions("myselect");

Above answer's code need a slight change to remove the list complete, please check this piece of code.

var select = document.getElementById("DropList");
var length = select.options.length;
for (i = 0; i < length;) {
  select.options[i] = null;
  length = select.options.length;
}

refresh the length and it will remove all the data from drop down list. Hope this will help someone.

The simplest solutions are the best, so You just need:

var list = document.getElementById('list');
while (list.firstChild) {
    list.removeChild(list.firstChild);
}

<select id="list">
  <option value="0">0</option>
  <option value="1">1</option>
</select>

for (var opt of document.querySelectorAll('#DropList option'))
{ 
  opt.remove();
}

This solution works with optgroups also.

while(document.getElementById("DropList").childNodes.length>0) 
{
    document.getElementById("DropList").removeChild(document.getElementById("DropList").childNodes[0]);
}

If you have to support IE and you have more than 100 items in your select list, I strongly recommend you consider replacing the select with a function like so:

function clearOptions(select) {
    var selectParentNode = select.parentNode;
    var newSelect = select.cloneNode(false); // Make a shallow copy
    selectParentNode.replaceChild(newSelect, select);
    return newSelect;
}

The select parameter should be the element either from a jquery selector or document.getElementBy call. The only downside to this is that you lose events you had wired up to the select, but you can easily reattach them as it is returned back out of the function. I was working with a select that had ~3k items and it would take 4 seconds on IE9 to clear the select so I could update it with the new content. Nearly instant doing it this way.

Today I was facing same problem, I did as below while reloading select box. (In Plain JS)

        var select = document.getElementById("item");
		select.options.length = 0;
		var opt = document.createElement('option');
		opt.value = 0;
		opt.innerHTML = "Select Item ...";
		opt.selected = "selected";
		select.appendChild(opt);


       for (var key in lands) {
			var opt = document.createElement('option');
		    opt.value = lands[key].id;
		    opt.innerHTML = lands[key].surveyNo;
		    select.appendChild(opt);
			
		}