Write a program to demonstrate the use of implementing interfaces.

Write a program to demonstrate the use of implementing interfaces.

Program Code:

import java.lang.*;

interface Area

{

final static float pi=3.14F;

float compute(float x,float y);

}

class rectangle implements Area

{

public float compute(float x,float y)

{

return(pi*x*y);

}

}

class circle implements Area

{

public float compute(float x,float x)

{

return(pi*x*x);

}

}

class interfacedemo

{

public static void main(String a[])

{

rectangle rect=new rectangle();

circle cir=new circle();

Area A;

A=rect;

System.out.println("Area of rectangle="+A.compute(10,20));

A=cir;

System.out.println("Area of circle="+A.compute(30,0));

}

}

Output:

Area of rectangle=628.0

Area of circle=2,827.43