Sets up the prototype chain and constructor property for a new class.

This should be called right after creating the class constructor.

function MySubClass() {}
createjs.extend(MySubClass, MySuperClass);
MySubClass.prototype.doSomething = function() { }

var foo = new MySubClass();
console.log(foo instanceof MySuperClass); // true
console.log(foo.prototype.constructor === MySubClass); // true

Finds the first occurrence of a specified value searchElement in the passed in array, and returns the index of that value. Returns -1 if value is not found.

 var i = createjs.indexOf(myArray, myElementToFind);

Promotes any methods on the super class that were overridden, by creating an alias in the format prefix_methodName. It is recommended to use the super class's name as the prefix. An alias to the super class's constructor is always added in the format prefix_constructor. This allows the subclass to call super class methods without using function.call, providing better performance.

For example, if MySubClass extends MySuperClass, and both define a draw method, then calling promote(MySubClass, "MySuperClass") would add a MySuperClass_constructor method to MySubClass and promote the draw method on MySuperClass to the prototype of MySubClass as MySuperClass_draw.

This should be called after the class's prototype is fully defined.

function ClassA(name) {
    this.name = name;
}
ClassA.prototype.greet = function() {
    return "Hello "+this.name;
}

function ClassB(name, punctuation) {
    this.ClassA_constructor(name);
    this.punctuation = punctuation;
}
createjs.extend(ClassB, ClassA);
ClassB.prototype.greet = function() {
    return this.ClassA_greet()+this.punctuation;
}
createjs.promote(ClassB, "ClassA");

var foo = new ClassB("World", "!?!");
console.log(foo.greet()); // Hello World!?!