[Ch2] All exercises

package ch2;

class DrumKit {

  boolean topHat = true;

  boolean snare = true;

  void playTopHat() {

    System.out.println("ding ding da-ding");

  }

  void playSnare() {

    System.out.println("bang bang ba-bang");

  }

}

class DrumKitTestDrive {

  public static void main(String[] args) {

    DrumKit d = new DrumKit();

    d.playSnare();

    d.snare = false;

    d.playTopHat();

    if (d.snare == true) {

      d.playSnare();

    }

  }

}

 No newline at end of file

package ch2;

public class EchoTestDrive {

  public static void main(String[] args) {

    Echo e1 = new Echo();

    Echo e2 = new Echo();   // correct answer

//       - or -

//    Echo e2 = e1;    // bonus "24” answer

    int x = 0;

    while (x < 4) {

      e1.hello();

      e1.count = e1.count + 1;

      if (x == 3) {

        e2.count = e2.count + 1;

      }

      if (x > 0) {

        e2.count = e2.count + e1.count;

      }

      x = x + 1;

    }

    System.out.println(e2.count);

  }

}

class Echo {

  int count = 0;

  void hello() {

    System.out.println("helloooo... ");

  }

}