javascript - jQuery / Programmatically Select an Option in Select Box

Question

I'm currently using jQuery to return some JSON results. Once these results are returned, I'm using them to pre-populate fields in my form.

However, I need some help in pre-selecting items in a drop down box. For example, I have a select box (this is shortened):

<select id="startTime">
<option value="14:00:00">2:00 pm</option>
<option value="15:00:00">3:00 pm</option>
<option value="16:00:00">4:00 pm</option>
<option value="17:00:00">5:00 pm</option>
<option value="18:00:00">6:00 pm</option>
</select>

And if my JSON value is:

 var start_time = data[0].start  // Let's say this is '17:00:00'

How can I, using jQuery, make the option with value '17:00:00' selected?

 <option value="17:00:00" selected="selected">5:00 pm</option>

Answer 1

update:

As of jQuery 1.9, jQuery has updated this functionality. The "selected" state of an option is actually a property, therefore jQuery has changed this to use the .prop() method. Syntax is very similar and easy to switch:

$('#startTime option[value=17:00:00]').prop('selected', true);

See http://api.jquery.com/prop/#entry-longdesc for why it needs to pass true.

---

Older jQuery

$('#startTime option[value=17:00:00]').attr('selected', 'selected');

or

$('#startTime option[value='+ data[0].start +']').attr('selected', 'selected');