INTERFACE - Program

interface area
{
final static double pi=3.14;
double compute(double x,double y);
}
class rectangle implements area
{
public double compute(double x,double y)
{
return(x*y);
}
}
class circle implements area
{
public double compute(double x,double y)
{
return(pi*x*x);
}
}
class iface
{
public static void main(String[]args)
{
rectangle rec=new rectangle();
circle cir=new circle();
area area;
area=rec;
System.out.println("rectangle"+area.compute(10,20));
area=cir;
System.out.println("circle"+area.compute(10,10));
}
}

OUTPUT

Z:\jdk1.4\bin>javac iface.java


Z:\jdk1.4\bin>java iface


rectangle200.0


circle314.0


Z:\jdk1.4\bin>