Sorting an array of objects with the sortBy method of Prototype

Here is an example of how easy it is to sort an array of objects using the Enumerable.sortBy method of the Prototype framework:

var obj1 = {
  lastName : "Lacava",
  firstName : "Alessandro"
};

var obj2 = {
  lastName : "Brown",
  firstName : "John"
};

var obj3 = {
  lastName : "Simpson",
  firstName : "Bart"
};

var arr = [obj1, obj2, obj3];

//order by last name
var sorted = arr.sortBy(function(obj) {
  return obj.lastName.toLowerCase();
}
);

var str = "";
sorted.each( function(obj, index) {
  str += index + 1 + " - " + obj.lastName + " " + obj.firstName;
}
);

//display the elements ordered by last name
document.write(str);