This property returns an object that implements the valueComparator protocol, which can be used as a comparator for performing case insensitive string sorting in descending order.
Note that if two comparisons differ only by case, it is not defined which element occurs before the other.
var arrayObj = shell.serviceManager.basics.array;
var comparator = shell.serviceManager.basics.comparator;
arrayObj.addValue("Basics");
arrayObj.addValue("Test");
arrayObj.addValue("test");
arrayObj.addValue("Test");
//The result will be "Basics" "Test", "Test", "test"
arrayObj.sort(comparator.stringAscending, "en-Us");