Question

Java

Question 4 3 pts Briefly answer these questions about interfaces on an example code segment. • What is an interface? • How is extending a class different from implementing an interface?

Answer 1

Interface: In a class, we have the variable, method and we can define method there and also we can initialize variable. But In the interface we can only give method signature means we can say Interface is a blueprint of a class. In java, we use Interface to get an abstraction and multiple inheritances.

eg:

interface findShape{

string getShape();

}

* we use interface keyword before any interface.

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class A extends B => Here B is a class

Here extends means class A will inherit all the methods and properties of class B.

class A implements C => Here C is an interface.

Here class A has to implement all the methods of interface C else it has to declare abstract.

So in general, extends means getting all the methods and properties from the parent class and Implements means defining all the method signatures of Interface.