Explain the concept of interfaces in java with a suitable example for the same?

Answer 1

interface works like an abstract class it has methods which are not defined its job is to give a general idea about the class(generic) the class can have its own functions but interface makes java program to include all the functions or methods present in the interface there are ibuilt interfaces like runnable example in threads it is runnable it makes compulsory to the class to include all the methods in interface if you dont want that then use abstract key word before class eg: interface a{void meth(int i);} class one implements a{ void meth(int i) System.out.print(i); //all other members of class// if dont use meth function it will give an error for big projects certain general functions are necessary which have to be there everywhere it gives general idea of what the program is doing

Answer 2

Ex:

public Interface Interface1 {

public String getName() {};

}

public Interface Interface2 {

public int getAge() {};

}

public class InterfaceExample implements Interface1, Interface2 {

public String getName() {

return "Anand";

}

public int getAge() {

return 28;

}

}

Here I have implemented two interfaces in a class. I must provide implementation for all the methods that are declared inside both interfaces. So for simplicity I have just written 1 method in each interface but in practical situations you may have numerous methods inside each interface.