Can Java interface have implementations?

Yes, it is possible . This is the catch: java does not support multiple inheritance, i.e. class cannot extend more than one class. However class can implement multiple interfaces.

Explanation: Concrete class implements an interface.

Implementations are the data objects used to store collections, which implement the interfaces described in the Interfaces lesson . The Java Collections Framework provides several general-purpose implementations of the core interfaces: For the Set interface, HashSet is the most commonly used implementation.

2. Why Interfaces Need Default Methods. Like regular interface methods, default methods are implicitly public; there’s no need to specify the public modifier. Unlike regular interface methods, we declare them with the default keyword at the beginning of the method signature, and they provide an implementation .11 Şub 2022

An interface in Java is a blueprint of a class. It has static constants and abstract methods.

All methods of an Interface do not contain implementation (method bodies) as of all versions below Java 8 . Starting with Java 8, default and static methods may have implementation in the interface definition.

The implements keyword is used to implement an interface . The interface keyword is used to declare a special type of class that only contains abstract methods. To access the interface methods, the interface must be “implemented” (kinda like inherited) by another class with the implements keyword (instead of extends ).