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09. Overriding, Overwriting or Overloading?

It seems these terms cause some confusion among developers who are new to OOP. In ActionScript, we only have overriding and overwriting, but no overloading (two out of three ain't bad - Meat Loaf).

Overriding means that a method or property steps in front of another and accepts the call. In the Math2.max() example, the new max() method overrides the original one in Math.max() (but uses it internally). Usually, overriding works with more than one class, with the subclass method or property overriding the superclass's method or property. This is also a form of polymorphism, meaning that there is more than one form (implementation) of a method. (Basically, having the same method name do different things.)

Overwriting is different in that the original no longer exists -- it is written over by (replaced with) another file, class, method, or property. In the TestClass example above, this block of code overwrites/replaces the method in the instance:

w.method = function() {
   trace("New method");
};

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