[jquery] how to change a selections options based on another select option selected?

here is my html.

<select id="type">
<option value="item1">item1</option>
<option value="item2">item2</option>
<option value="item3">item3</option>
</select>

<select id="size">
<option value="">-- select one -- </option>
</select>

here is the jquery i tried but was unsuccessful.

$(document).ready(function() {

if( $("#type").val("item1"))
{
  $("#size").html("<option value='test'>test</option><option value="test2">test2</option>);
}
elseif( $("#type").val("item2"))
{
   $("#size").html("<option value='anothertest1'>anothertest1</option>");
}

});

basically what i'm trying to do is if an option is selected in #type then the size select is populated with options associated to it. how can i do this?

thanks

This question is related to jquery

The answer is


as a complementary answer to @Navid_pdp11, which will enable to select the first visible item and work on document load as well. put the following below your body tag

<script>
$('#mainCat').on('change', function() {
    let selected = $(this).val();
    $("#expertCat option").each(function(){
        let element =  $(this) ;
        if (element.data("tag") != selected){
            element.removeClass('visible');
            element.addClass('hidden');
            element.hide() ;
        }else{
            element.removeClass('hidden');
            element.addClass('visible');
            element.show();
        }
    });
    let expertCat = $('#expertCat');
    expertCat.prop('selectedIndex',expertCat.find("option.visible:eq(0)").index());
}).triggerHandler('change');
</script>

Your if statement is setting the value. You want to compare it by doing this

if ($("#type").val() == "item1") {
 ...
}

daLizard is right though. You want an event handler. document.ready runs only once, when the page DOM is ready to be used.


Here is my simple solution using Jquery filters.

$('#publisher').on('change', function(e) {
   let selector = $(this).val();
   $("#site > option").hide();
   $("#site > option").filter(function(){return $(this).data('pub') == selector}).show();
});

JSFIDDLE


I don't quote understand what you are trying to achieve, but you need an event listener. Something like:

$('#type').change(function() {
   alert('Value changed to ' + $(this).attr('value'));
});

This will give you the value of the selected option tag.


you can use data-tag in html5 and do this using this code:

_x000D_
_x000D_
<script>_x000D_
 $('#mainCat').on('change', function() {_x000D_
  var selected = $(this).val();_x000D_
  $("#expertCat option").each(function(item){_x000D_
   console.log(selected) ;  _x000D_
   var element =  $(this) ; _x000D_
   console.log(element.data("tag")) ; _x000D_
   if (element.data("tag") != selected){_x000D_
    element.hide() ; _x000D_
   }else{_x000D_
    element.show();_x000D_
   }_x000D_
  }) ; _x000D_
  _x000D_
  $("#expertCat").val($("#expertCat option:visible:first").val());_x000D_
  _x000D_
});_x000D_
</script>
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>_x000D_
<select id="mainCat">_x000D_
   <option value = '1'>navid</option>_x000D_
   <option value = '2'>javad</option>_x000D_
   <option value = '3'>mamal</option>_x000D_
  </select>_x000D_
  _x000D_
  <select id="expertCat">_x000D_
   <option  value = '1' data-tag='2'>UI</option>_x000D_
   <option  value = '2' data-tag='2'>Java Android</option>_x000D_
   <option  value = '3' data-tag='1'>Web</option>_x000D_
   <option  value = '3' data-tag='1'>Server</option>_x000D_
   <option  value = '3' data-tag='3'>Back End</option>_x000D_
   <option  value = '3' data-tag='3'>.net</option>_x000D_
  </select>
_x000D_
_x000D_
_x000D_


You can use switch case like this:

_x000D_
_x000D_
$(document).ready(function () {_x000D_
  $("#type").change(function () {_x000D_
     switch($(this).val()) {_x000D_
        case 'item1':_x000D_
            $("#size").html("<option value='test'>item1: test 1</option><option value='test2'>item1: test 2</option>");_x000D_
            break;_x000D_
        case 'item2':_x000D_
            $("#size").html("<option value='test'>item2: test 1</option><option value='test2'>item2: test 2</option>");_x000D_
            break;_x000D_
        case 'item3':_x000D_
            $("#size").html("<option value='test'>item3: test 1</option><option value='test2'>item3: test 2</option>");_x000D_
            break;_x000D_
        default:_x000D_
            $("#size").html("<option value=''>--select one--</option>");_x000D_
     }_x000D_
  });_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<select id="type">_x000D_
    <option value="item0">--Select an Item--</option>_x000D_
    <option value="item1">item1</option>_x000D_
    <option value="item2">item2</option>_x000D_
    <option value="item3">item3</option>_x000D_
</select>_x000D_
_x000D_
<select id="size">_x000D_
    <option value="">-- select one -- </option>_x000D_
</select>
_x000D_
_x000D_
_x000D_