Inheritance

Extending Interfaces

When one interface inherits from another interface, that "subinterface" acquires all the method definitions and constants that its "superinterface" defined.

To extend an interface, we use the extends keyword just as you do in a class definition:

public interface Fruitlike extends Foodlike { ... }

In multiply inherited interfaces, the rules for managing method name conflicts are the same as for classes that use multiple interfaces; methods that differ only in return type will result in a compiler error.