Develop Reference

Selected attribute of select options is not updating automatically

I have multiple selects on my page, each has multiple options.
However, If I select an option then the attribute selected of the option is not updating. Shouldn't this happen automatically?!
Example:
<select id="browsers">
<option value="Firefox">Bing</option>
<option value="InternetExplorer" selected="selected">Internet Explorer</option>
<option value="Chrome">Chrome</option>
</select>
By inspecting the DOM with the developer console, you should see, that the selected attribute is not changing even after selecting another option.
However I found a workaround. To solve this issue we can use this code:
$(document).on("change","select",function() {
$("option[value=" + this.value + "]", this)
.attr("selected", true).siblings()
.removeAttr("selected")
});
Example:
$(document).on("change","select",function() {
$("option[value=" + this.value + "]", this)
.attr("selected", true).siblings()
.removeAttr("selected")
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="browsers">
<option value="Firefox">Bing</option>
<option value="InternetExplorer" selected="selected">Internet Explorer</option>
<option value="Chrome">Chrome</option>
</select>
This works kind of. However, If I select another option than the default option, e.g. Chrome and reload the page, then the option Chrome is still selected even after reload, BUT the selected attribute still points to Internet Explorer!
Which is the best approach to solve this?
My idea is to run through all selects on $(document).ready() and select the option where the selected attribute points to.
But why does this all not happen automatically?
Is it a bug or a feature?

The selected attribute defines if an element should be selected on pageload. If you post a form with a select element, the chosen option will be the one posted, regardless of the initial selected element.
What do you need the selected-attribute for in your case?
Edit: Based on your comments I made a fiddle
Fiddle 1 https://jsfiddle.net/q3fpafov/1 selects like you want
Fiddle 2 https://jsfiddle.net/bge9bsa7/2/ only files available for a chosen language are shown
I hope it's somewhere along the lines of what you're looking for.
The reason for your option still being selected when you reload is browser based. But the selected-attribute does nothing for the usability of the option. Also, it won't change because you don't change the way the HTML-element itself is being rendered (at page load)

Note: selected="selected" is not necessary, simply selected attribute will work as well.
When present, select attribute specifies that an option in select should be pre-selected when the page loads.
Also, the pre-selected option will be displayed first in the drop-down list.
Those 2 should be only effects of the selected attribute.
Note the keywords - when the page loads. He is either there or not when a browser loads the page.
If you wanna make it dynamic you need to use JavaScript. What do you wanna achieve with this? Having attribute selected on the correct element when reloading page or programmatically select the correct element after the page has been loaded?
If you simply wanna make element selected there is easier way trough either value:
jQuery("#browsers[value='the value of the one you like']").attr('selected','selected');
Or by index (mind, indexes start at 0 not 1):
document.getElementById("browsers").selectedIndex = "2";

The problem before was, that after selecting an option and reloading the page, the option was remembered during page reload, even though the attribute selected pointed to another option.
I solved it by calling the function below everytime. The function finds out which is the truly selected option, even after page reload.
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select class="downloadSelect" id="select_179">
<option value="-">Please select</option>
<option value="link_2748" selected="selected">Deutsch</option>
<option value="link_2749">Chinese</option>
</select>
<button onclick="return showSelectedOption('select_179');">Show Option Text</button>
<script>
function showSelectedOption(pSelectID)
{
var text;
$("#"+pSelectID)
.find("option")
.each(function(){
if ($(this).prop("selected")) {
text = $(this).text();
}
});
console.log(text);
}
</script>

You can check the value of the select when it changes to see what it has been changed to.
var select = document.getElementById('browsers');
select.addEventListener('change', function(e) {
localStorage.setItem('browser', this.value);
});
var browser = localStorage.getItem('browser');
if (browser) {
select.value = browser;
}
<select id="browsers">
<option value="Firefox">Firefox</option>
<option value="InternetExplorer" selected="selected">Internet Explorer</option>
<option value="Chrome">Chrome</option>
</select>
edit
So, I missed the part about storing the value so that it persists when the page is reloaded, and depending on the OP's use case, I would suggest using localStorage to save the value when it is changed, and to read from it when the page is reloaded.
I have edited the snippet to reflect this (code is simplified)

Want to add none as value in select multiple

I am using chosen.jquery.js for select field
<select chosen multiple data-placeholder="Select Body Part(s)"
ng-options="option.Name as option.Name for option in BodyPartList" ng-model="Body_Part">
<option value="" disabled>Select Body Part(s)</option>
</select>
But It shows only data-placeholder value in case of no data in model.
I want to show "Select Body Part(s)" as a option in list.
And user must not select this. Reason is that, I want to add dynamic "Unknown" value in list of Body_Parts. But it not reflect in list.
Same work for select having single selection.

I'm not seeing any problems with your code, as such. Like, I'm trying it and getting the visual behaviour I think you're wanting? Am I missing something?
Html just yours with ng-app etc, javascript is:
var myApp = angular.module('myApp', ['localytics.directives']);
myApp.controller('MyController', function($scope) {
$scope.BodyPartList = [
{ Name: "Arm" },
{ Name: "Leg" }
];
$scope.Body_Part = [];
});
Not sure if data-placeholder is actually doing anything.
Fiddle: http://jsfiddle.net/7187f6d9/
That said, it's not "working". In the fiddle I put a regular select box alongside the chosen one, and the chosen one doesn't seem to be writing to the ng-model correctly. I'm not sure what's up with that.

You can choose the below option
https://harvesthq.github.io/chosen/#optgroup-support
or push another item to the top of the array from server side as your custom label and disable it on client side with the help of ng-if and $index properties of ng-repeat and angularjs. If this make sense then its fine else i can give you a demo.

I hope your query is, you want show a place holder as current selected value but user shouldn't be able to select it.
Instead of making it disabled, make ithidden. Then display an error if a user doesn't select any other options, using the value of placeholder option.
A sample snippet is added below. If value of select is Error, write a case to throw a error back to user.
<select>
<option value="Error" hidden>Select any Company</option>
<option value="Toyota">Toyota</option>
<option value="Nissan">Nissan</option>
<option value="BMW">BMW</option>
</select>
Hope this helps! If not, ping me with your query. :)

How do I show the selected value of select2?

I am trying to set the value dynamically to my combobox on which I have applied select2 jQuery class. After applying code it sets the value to that combobox; but it still says "Select one".
Can anyone help me to show the selected value? Please.
HTML:
<select id="cmboDemo">
<option value="">Select one</option>
<option value="Bob">Bob</option>
<option value="Scott">Scott</option>
</select>
Javascript:
$("#cmboDemo").select2();
//....
$("#cmboDemo").val("Scott");
...//
In result scott is selected but combobox shows "Select one".

Remove $("#cmboDemo").select2();
and use the second one only:
$("#cmboDemo").val("Scott");

By using select2.js some additional layers of css are overlapped actual combo-box. By using all above code the value is set to select box; but because of that upper style layer it shows first value. i.e Select one.
So by changing that upper layer's text will fixed the problem.
This is the final outcome:
$("#select2-cmboDemo-container").text("Scott");
Thanks.

How to get the selected value of some random dropdown in Javascript/jQuery

<select ng-model="myModel" id="searchAsset" class="search">
<option ng-repeat="asset in assettype" ng-click="assetclick()" value="{{asset}}"></option>
</select>
<select class="search" id="searchLevel">
<option class="chooseLevel" ng-repeat="level in levellist" value="{{level}}"></option>
</select>
While performing some logic on second dropdown, I want to fetch the selected value of the first dropdown or vice-versa. How can I do this?
I tried using $("#searchLevel").value and $("#searchLevel option:selected").text()

The direct answer to this question is to use the .val() method for jQuery like so:
var selectedVal = $("#searchLevel").val();
However, the slightly less direct, but true answer is that you should not be doing anything like this in an angular app - changes in the dom should only be affecting your view model.

When your using angular, jquery is really not required.
As per your code, The first select menu value will be stored in the ng-model attribute value i.e. myModel.
In your second select menu, specific the ng-model as well. You can just fetch the value of the drop down menu by calling ng-model name.
<select class="search" id="searchLevel" ng-model="secondSelect">
<option class="chooseLevel" ng-repeat="level in levellist" value="{{level}}"></option>
</select>
For example,
If you want to access the value inside your controller on change event, then
$scope.changeEventhandlerForFirstSelect = function() {
// $scope.myModel will contain the value
}
Similarly, for second select menu $scope.secondSelect will give that value.

try
$("#searchLevel").val();
with: $("#searchLevel option:selected").text() you get the text not the value.

JS/Jquery: how to check whether dropdown has selected values?

I've googled and tried a number of ways to do this but none work for me so far. What I am looking for is quite simple: I want to be able to tell whether a dropdown has a selected value or not. The problem is that selectedIndex, :selected, val(), etc. do return results for the following case:
<select>
<option value="123">123</option>
<option value="234">234</option>
</select>
Obviously the browser will display this dropdown with the 123 option being selected but it will be selected only because there are no other options, in reality this dropdown doesn't have a selected value because there is no "selected" property. So basically I am trying to find how to tell apart the above dropdown from this one
<select>
<option selected value="123">123</option>
<option value="234">234</option>
</select>

var hasValue = ($('select > [selected]').length > 0);
Alternatively,
var hasValue = $('select').has('[selected]');

Quick solution:
<select>
<option selected></option>
<option value="123">123</option>
<option value="234">234</option>
</select>
Then see if you have a .val()

The approved answer doesn't seem to work for me.
Here is how I do it to check if all select options are selected:
if($('select option:selected').length > 0) {
/* Do your stuff here */
}

As far as I can tell, there is no functional distinction between your two examples. Essentially, the browser automatically selects the first option.
See, for example, the result of
$('option:selected')
on your first example.
If you really want to prevent this happening, you have two options. The first is to introduce a new, empty element into the select, per Jason's answer. The other option is to deselect the automatically selected value:
$(document).load(function(){
$('option:selected').attr('selected', false);
});
This clears the selection. Any result of $('select').val() that isn't an empty string will therefore be a change by the user.