Check if value is in select list with JQuery

Use the Attribute Equals Selector

var thevalue="foo";
var exists = 0 != $('#select-box option[value="+thevalue+"]').length;

If the option’s value was set via Javascript, that will not work. In this case we can do the following:

var exists = false;
$('#select-box option').each(function(){
    if (this.value == 'bar') {
        exists = true;
        return false;
    }
});