Excersise : 6 Using Interface | Java | Tamizhan Goals

Excersise: 6

    Develop a Program using Interface.

Program

import java.io.*;
import java.lang.*;
interface demo
{
	double pi=3.14;
	void area(double r);
}
class circle implements demo
{
	double radius;
	double carea;
	public void area(double r)
	{
		radius=r;
		carea=pi*radius*radius;
		System.out.println("Area of Circle:"+carea);
	}
}
class Intdemo
{
	public static void main(String arg[])throws IOException
	{
		DataInputStream din=new DataInputStream(System.in);
		System.out.println("Enter the Value of Radius:");
		double ra=Double.parseDouble(din.readLine());
		circle c=new circle();
		c.area(ra);
	}
}

Output