Actionscript 3: What's difference between interface and abstract and when to use them..?

I was wondering the differences between abstract and interface in actionscript 3 and when to u开发者_如何学Pythonse them..I have searched google but still couldn't understand them....I hope someone here can give me few tips...Thanks a lot!!!

The difference is that interface is valid actionscript, but abstract is not...

Now, in other languages you can mark a method or a class as abstract. This is somewhat like an interface, in that abstract means it has no implementation (for a method) or cannot be instantiated (for a class).

So, if a class is abstract, it means you cannot create an instance diretly (with new), but rather you have to extend the class to access its functionality.

An abstract method is pretty much like a method defined in an interface. When you extend a class that declares an abstract method, you have to provide an implementation that has the same signature, or your code won't compile. An abstract method makes the class abstract automatically, because otherwise you would be able to create an instance of an object that has an unimplemented method.

With an abstract class, you have some of the features of an interface (i.e. you define a method whose concrete implementation has to be provided) but you also can have other methods that are implemented and ready to use.

(This is a general explanation; maybe this is bit different in language X, but I think this gives you the basic idea)