How to check if an option is selected?

UPDATE

A more direct jQuery method to the option selected would be:

var selected_option = $('#mySelectBox option:selected');

Answering the question .is(':selected') is what you are looking for:

$('#mySelectBox option').each(function() {
    if($(this).is(':selected')) ...

The non jQuery (arguably best practice) way to do it would be:

$('#mySelectBox option').each(function() {
    if(this.selected) ...

Although, if you are just looking for the selected value try:

$('#mySelectBox').val()

If you are looking for the selected value's text do:

$('#mySelectBox option').filter(':selected').text();

Check out: http://api.jquery.com/selected-selector/

Next time look for duplicate SO questions:

Get current selected option or Set selected option or How to get $(this) selected option in jQuery? or option[selected=true] doesn't work

You can get the selected option this way:

$('#mySelectBox option:selected')...

LIVE DEMO

But if you want to iterate all the options, do it with this.selected instead of this.isChecked which doesn't exist:

$('#mySelectBox option').each(function() {
    if (this.selected)
       alert('this option is selected');
     else
       alert('this is not');
});

LIVE DEMO

Update:

You got plenty of answers suggesting you to use this:

$(this).is(':selected') well, it can be done a lot faster and easier with this.selected so why should you use it and not the native DOM element method?!

Read Know Your DOM Properties and Functions in the jQuery tag info

You can use this way by jquery :

$(document).ready(function(){
 $('#panel_master_user_job').change(function () {
 var job =  $('#panel_master_user_job').val();
 alert(job);
})
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select name="job" id="panel_master_user_job" class="form-control">
                                    <option value="master">Master</option>
                                    <option value="user">User</option>
                                    <option value="admin">Admin</option>
                                    <option value="custom">Custom</option>
                                </select>