CODEWITHSUNDEEP
jquery
BuZz
BuZz

Reputation: 17475

What is a safe way to check that a listbox is empty in JQuery?

What is a safe way to check that a listbox is empty in JQuery ? Alternative question, how to check if there is no item actively selected ?

I have tried :

if(...  .val() != "null")

also 

if(...  .val() != null)

as I spotted null value on val() while debugging when the list is empty or nothing is selected, but doesn't seem to work accurately.

Upvotes: 0

Views: 5601

Answers (4)

sQuijeW
sQuijeW

Reputation: 194

best to use 

    $('select#myselect option').length;

or

    $(myselct).find('option').length;

to get the length

ex:

    var x = $(myselct).find('option').length;
    if (x > 0){'if listbox contains items}

Upvotes: 1

Nick Benedict
Nick Benedict

Reputation: 557

tests if any item is selected. if true, an item is selected and will display the slected value.

if($("#Select").val() != null){
  alert($("#Select").val());
}

tests if any item is not selected . if true is no items are selected

  if($("#Select").val() == null){
      alert("no items selected.);
    }

Upvotes: 0

Jasper
Jasper

Reputation: 76003

To check if there are <option> elements inside the <select> element:

if ($('#my-select').children().length == 0) {
    alert('OH NO, there aren\'t any options to select!');
}

To check to see if an <option> inside the <select> has been selected (only works if selected <option> element has a value attribute)

if (typeof($('select').children(':checked').val()) == 'undefined') {
    alert('No Option with a Value Selected');
}

Here is a demo: http://jsfiddle.net/sJdBJ/

Some Docs:

Upvotes: 5

Saeed Neamati
Saeed Neamati

Reputation: 35832

I usually use pure JavaScript for this:

$('#select-id')[0].selectedIndex == -1;

Please note that $('#select-id')[0] converts back the jQuery object to JavaScript object.

Upvotes: 1

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