Java---interface

Features of the interface:

1. Implement the subclass of the interface, must all implement the abstract method in the interface. Otherwise, it is an abstract class.

2. Interfaces cannot be instantiated.

3. The interface is used to be implemented. The relationship--------------classes and interfaces is the implementation relationship. (Interface: interface implementation: Implement)

Code:

Class Demo Implements inter{

Inside to implement the method in the interface;

}

Between classes and classes is an inheritance relationship

Classes and interfaces are implementation relationships

Interfaces and interfaces can be inherited, and multiple inheritance

Java---interface