JQuery select2 set default value from an option in

问题:

I want to be able to set the default/selected value of a select element using the JQuery Select2 plugin.

回答1:

One more way - just add a selected = "selected" attribute to the select markup and call select2 on it. It must take your selected value. No need for extra JavaScript. Like this :

Markup

<select class="select2">
   <option id="foo">Some Text</option>
   <option id="bar" selected="selected">Other Text</option>
</select>

JavaScript

$('select').select2(); //oh yes just this!

See fiddle : http://jsfiddle.net/6hZFU/

Edit: (Thanks, Jay Haase!)

If this doesn't work, try setting the val property of select2 to null, to clear the value, like this:

$('select').select2("val", null); //a lil' bit more :)

After this, it is simple enough to set val to "Whatever You Want".

回答2:

One way to accomplish this is...

$('select').select2().select2('val', $('.select2 option:eq(1)').val());

So basically you first initalize the plugin then specify the default value using the 'val' parameter. The actual value is taken from the specified option, in this case #1. So the selected value from this example would be "bar".

<select class=".select2">
  <option id="foo">Some Text</option>
  <option id="bar">Other Text</option>
</select>

Hope this is useful to someone else.

回答3:

$("#id").select2("val", null); //this will not work..you can try

You should actually do this...intialise and then set the value..well this is also the way it worked for me.

$("#id").select2().select2("val", null);
$("#id").select2().select2("val", 'oneofthevaluehere');

回答4:

The above solutions did not work for me, but this code from Select2's own website did:

$('select').val('US'); // Select the option with a value of 'US'
$('select').trigger('change'); // Notify any JS components that the value changed

Webpage found here

Hope this helps for anyone who is struggling, like I was.

回答5:

For 4.x version

$('#select2Id').val(__INDEX__).trigger('change');

to select value with INDEX

$('#select2Id').val('').trigger('change');

to select nothing (show placeholder if it is)

回答6:

For ajax select2 multiple select dropdown i did like this;

  //preset element values
  //topics is an array of format [{"id":"","text":""}, .....]
        $(id).val(topics);
          setTimeout(function(){
           ajaxTopicDropdown(id,
                2,location.origin+"/api for gettings topics/",
                "Pick a topic", true, 5);                      
            },1);
        // ajaxtopicDropdown is dry fucntion to get topics for diffrent element and url

回答7:

    $('select').select2("val",null);

回答8:

If you are using an array data source you can do something like below -

$(".select").select2({
    data: data_names
});
data_names.forEach(function(name) {
    if (name.selected) {
        $(".select").select2('val', name.id);
    }
});

This assumes that out of your data set the one item which you want to set as default has an additional attribute called selected and we use that to set the value.

回答9:

How is this?

Markup

<select>
   <option value="foo">Some Text</option>
   <option value="bar">Other Text</option>
</select>

JavaScript

$('select').val('bar').select2();

回答10:

Don't know others issue, Only this code worked for me.

$('select').val('').select2();