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need some notes
Posted by aziz on January 12, 2002 at 7:37 AM
> What is the differences between the inheriance methods used by java and C++
> > > Is their anyway (through either inheritance or interfaces)
> > > to declare an abstract static method? I would like
> > > to use polymorphism for several classes and I would
> > > like all of them to have static method.
> > > I know I could do this by having the static method (not
> > > abstract) in the super class and then overriding the
> > > method in the subclasses, but I would like to have the
> > > method abstract so it would be required to rewrite the
> > > method to create the subclass.
> > I'm afraid you can't always get what you want. Java has no
> > abstract static methods. Abstract methods are bound up in
> > the polymorphism thing. They are intended to provide
> > templates for subclasses not to simply "rewrite" but to
> > "override" -- so that when they are invoked from a superclass
> > reference type, dynamic binding causes the appropriate
> > subclass implementation of the method to run. Static methods
> > are bound at compile time based on the type of the reference,
> > not at run time based on the class of the object. When you
> > rewrite a static method in a subclass, you aren't "overridding"
> > the superclass version of the method, but simply "hiding" it.
> > But if you invoke the method on a superclass type reference to
> > the subclass object, you'll still just get the superclass
> > implementation of the method. Even though your holding a
> > reference to a subclass object, the static method
> > implementation to invoke is decided at compile time based on
> > the type of the reference, which is the superclass.
> > bv
> > invoke