ControlFlow Demo in Java.

ControlFlow.java

/*
 * Control Flow Demo.
 *
 * Constructor call always starts from the top superclass down to subclasses.
 */

class A {
  // A(int x) { // It'll generate an error, as there is no default constructor defined.
  A() {
    // super(); // Invisible call which invoke superclass constructor (Object).
    System.out.println("From class A");
  }
}

class B extends A {
  B() {
    // super(); // Invisible call which invoke superclass constructor (A).
    // super(100); // If used, it'll try to invoke parameterised constructor of superclass.
    System.out.println("From class B");
    // super(); // error: call to super must be first statement in constructor
  }
}

class C extends B {
  C() {
    // super(); // Invisible call which invoke superclass constructor (B).
    System.out.println("From class C");
  }
}

class ControlFlow {
  public static void main(String[] args) {
    new C();
  }
}