Sorting options elements alphabetically using jQuery

What I’d do is:

1. Extract the text and value of each <option> into an array of objects;
2. Sort the array;
3. Update the <option> elements with the array contents in order.

To do that with jQuery, you could do this:

var options = $('select.whatever option');
var arr = options.map(function(_, o) { return { t: $(o).text(), v: o.value }; }).get();
arr.sort(function(o1, o2) { return o1.t > o2.t ? 1 : o1.t < o2.t ? -1 : 0; });
options.each(function(i, o) {
  o.value = arr[i].v;
  $(o).text(arr[i].t);
});

Here is a working jsfiddle.

edit — If you want to sort such that you ignore alphabetic case, you can use the JavaScript .toUpperCase() or .toLowerCase() functions before comparing:

arr.sort(function(o1, o2) {
  var t1 = o1.t.toLowerCase(), t2 = o2.t.toLowerCase();

  return t1 > t2 ? 1 : t1 < t2 ? -1 : 0;
});