Imple.java

/*
 * Imple.java
 *
 * - Interface can have variables which are public, static and final.
 *
 * Usage:
 *   javac Imple.java && java MainClass
 */

interface A {
  int x = 1000;
  void getA();
}

interface B {
  int x = 2000;
  void getB(); 
}

interface C extends A, B {
  void getC();
}

class Imple implements C { // The same as implements A, B
// class Imple implements A, B {
// class Imple implements A, B, C {
  Imple() {
   // System.out.println(x); // error: reference to x is ambiguous, both variable x in A and variable x in B match.
   // A.x = 3000; // error: cannot assign a value to final variable x
   System.out.println(A.x);
   System.out.println(B.x);
  }
  public void getA() {
   System.out.println("from getA()");
  }
  public void getB() {
   System.out.println("from getB()");
  }
  public void getC() {
   System.out.println("from getC()");
  }
}

class MainClass {
  public static void main(String[] args) {
   // new Imple();
   Imple i1 = new Imple();
   i1.getA();
   i1.getB();
   i1.getC();
  }
}