TurtleTest.java Questions

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Program listing

 
// LINKED LIST TUTORIAL
// Copyright (C) 1998-2016 Davin Pearson
// Website: http://davin.50webs.com/java-tutorials

class Turtle {

  /*
   * Properties of the class...
   */
  private String name;
  private int    age;
  private int    weight;
  private Turtle up;

  /*
   * Constructor of the class...
   */
  public Turtle(String aName, int anAge, int aWeight) {
    name   = aName;
    age    = anAge;
    weight = aWeight;
  }

  /*
   * A method for one turtle to sit on top of another:
   *
   */
  public void carry(Turtle onTop) {

    // body goes here:

  }

  /*
   *
   * This method lists all the Turtles that the current Turtle
   * is carrying on his or her back.
   *
   */
  public void tellStory() {

    System.out.println("Turtle " + name +
                       " is carrying the following turtles: ");

    // for-loop goes here:

  }
}
^L

class TurtleTest {

  /*
   *
   * The main method is the point of entry into the program...
   *
   */
  public static void main(String[] args) {

    Turtle yertle = new Turtle("Yertle", 100, 20);
    Turtle zippy  = new Turtle("Zippy",  100, 20);
    Turtle bungle = new Turtle("Bungle", 100, 20);

    bungle.carry(zippy);
    zippy.carry(yertle);

    System.out.println("The arrangement of the turtles is as follows:");

    bungle.tellStory();       // => "Bungle is carrying: Zippy, Yurtle"
    zippy.tellStory();        // => "Zippy is carrying: Bungle"
    yertle.tellStory();       // => "Yurtle is carrying: no-one"

    System.out.println("Bungle is carrying the following weight:");

    System.out.println(bungle.calculateLoad()); // => 60
  }

}

// QUESTIONS:
//
// (1) Finish the method carry()
// 
// (2) Finish the method tellStory()
// 
// (3) Write a method findTopTurtle() that returns a reference to the
// Turtle at the top of the pile.
// 
// (4) Write a method isAtTop() which returns whether or not the
// current Turtle is at the top of the pile.
// 
// (5) Write the method calculateLoad() that returns the total weight of
// all the Turtles sitting on the current one.
// 
// (6) Write the method findOldestTurtle() that returns a
// reference to the oldest Turtle in the pile, starting from
// the current one.
// 
// (7) What is the advantage in having the fields name, age and weight
// private?
// 
// (8) How could we have it so that other classes could read the name, age,
// and weight of the Turtles, but not be allowed to change the name, age
// and weights?
// 
// (9) What is the advantage in having the property "up" private?
// 
// (10) Write a method called insert(Turtle aTurtle) that inserts
// aTurtle after the current Turtle in the list.
// 
// (11) HARDER: Rewrite the tellStory method using recursion.  Note that
// you will need two functions instead of one.
//