Contoh Sederhana Program Java

public class lingkaran {

public static void main (String []args) {
float phi=3.14f;
float r=7;
double luas;
luas=phi*r*r;
String nama,npm;
nama="Priyo Santoso";
npm="55410403";
System.out.println("Nama=Priyo Santoso");
System.out.println("NPM=55410403");

System.out.println("Luas Lingkaran");

System.out.println("jari-jari="+r);
System.out.println("Luas lingkaran="+luas);
}