Why interface extends interface

An interface may be declared to be a direct extension of one or more other interfaces, meaning that it implicitly specifies all the member types, abstract methods, and constants of the interfaces it extends, except for any member types and constants that it may hide. Python Javascript Linux Cheat sheet Contact.

Can an interface extend multiple interfaces in Java? Yes, you can do it. Asked 6 years, 7 months ago. Active 3 years, 4 months ago.

Viewed 3k times. Wouldn't it make more sense if B implemented A? Improve this question. Because an interface couldn't implement anything before default methods where a thing. JLS 9. Superinterfaces and Subinterfaces : "Any class that implements the declared interface is also considered to implement all the interfaces that this interface extends.

Add a comment. Active Oldest Votes. Improve this answer. Zibbobz Zibbobz 1, 2 2 gold badges 12 12 silver badges 20 20 bronze badges. Note that even though class XYZ is implementing the interface B, the interface A is automatically available to the class as interface B is extending the interface A.

In fact, an interface can extend multiple interfaces like below. The interface B is extending interface A and interface C. In this multiple interface extends example, the interface B is extending interfaces A and C.

But, methods from all the interfaces are available to the class. An interface declaration consists of modifiers, the keyword interface , the interface name, a comma-separated list of parent interfaces if any , and the interface body. For example:. The public access specifier indicates that the interface can be used by any class in any package. If you do not specify that the interface is public, then your interface is accessible only to classes defined in the same package as the interface.

An interface can extend other interfaces, just as a class subclass or extend another class.