Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

No instantiation: You can use both abstract classes and interfaces to define types that cannot be instantiated. Instead, you must implement an interface or extend an abstract class by other types. ...

I'm trying to model some data in code and i'm a bit confused on what should be an abstract class vs an interface, and why i can't override an abstract property with a property of an inherited type ...

interface reader; read: method return=num; cpy: method n: num return=string; endinterface; Use SAVECLASS to create an interface entry with two abstract methods, READ and CPY. The abstract methods are ...