Java basics: interfaces and java basic interfaces

Java basics: interfaces and java basic interfaces

I. Example

Ii. Summary

1: an interface is a set of definitions of abstract methods and constant values.
2: in essence, an interface is a special abstract class that only contains the definition of constants and methods. There is no method implementation.
3. Multiple implementations of interfaces
4: The attribute declared in the interface is public static final by default, and can only be public static final.
5: only abstract methods can be defined in the interface. The default value is public or public.
6. interfaces can inherit other interfaces and add new attributes and abstract methods.