RunnerTest.java Questions

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

class SportsShoe
{

   /*
    * Properties of the class...
    */
   public String model;        // what kind of shoe it is
   public double speedBoost;   // the boosting factor of the shoe

   // constructor goes here:







   /*
    * This method allows you to print the current sports shoe.
    *
    */
   public String toString()
   {
      return ("I am a shoe called " + model +
              " and my boosting factor is " + speedBoost);
   }

}

class Runner
{
   /*
    * Properties of the class...
    */
   private String     name;     // Runner's name.
   private int        speed;    // speed of runner in km/hr.
   private SportsShoe shoes;    // which shoe they are wearing

   // constructor goes here:








   /*
    * This method allows you to print the current runner.
    *
    */
   public String toString()
   {
      return ("I am a runner and my name is " + name +
              " and the name of my shoes is " + shoes.name);
   }

   /*
    *
    * This private method computeSpeed works out the runners speed,
    * based on their basic speed and the speed boost due to the
    * SportsShoe that they are currently wearing.
    *
    */

   // method goes here:








   /*
    * Prints the result of racing two runners against each other.
    *
    */
   public static void race(Runner r1, Runner r2)
   {
      if (r1.computeSpeed() > r2.computeSpeed())
      {
         System.out.println("Runner " + r1.name +
                            " beats " + r2.name);
      }
      else
      {
         System.out.println("Runner " + r2.name +
                            " beats " + r1.name);
      }
   }

   /*
    * Swaps the shoes of two runners.
    */
   public static void swapShoes(Runner r1, Runner r2)
   {
      SportsShoe tempShoe = r1.shoes;
      r1.shoes = r2.shoes;
      r2.shoes = tempShoe;
   }
}

class RunnerTest
{
   /*
    *
    * The main method is the point of entry into the program...
    *
    */
   public static void main(String[] args)
   {
      SportsShoe nike    = new SportsShoe("Nike NX-71",   2.0);
      SportsShoe reebock = new SportsShoe("Reebock R20",  2.3);
      SportsShoe puma    = new SportsShoe("Puma P200-MMX",4.8);

      Runner sg = new Runner("Speedy Gonzalez", 55, nike);
      Runner sw = new Runner("Slick Willy",     49, reebock);
      Runner fa = new Runner("Fat Albert",      15, puma);

      Runner.race(sg,sw);
      // Runner.race(sg,sw,fa);
      // sg.raceAgainst(sw);
   }
}

// QUESTIONS:
//
// (1) Write constructors for the classes SportsShoe and
// Runner, by looking at the main method to see how many
// arguments each constructor has.
// 
// (2) In the Runner class, write the private method
// computeSpeed that has no arguments and returns a
// double-precision floating point value that equals the
// runner's running speed.

// The speed of a runner is determined by multiplying their
// "speed" property with the "speedBoost" property of the
// shoes that they are wearing.  For example, Speedy
// Gonzalez's running speed = 55 * 2.0 = 110.0.
// 
// (3) Fix the "race" method so that it checks for a draw.
// 
// (4) By copying the "race" method, write a three-parameter
// race method for racing three runners against each other.
// Two methods in the same class with the same name is
// called "overloading" in Java.  Add a call to this method
// from the main method.
// 
// (5) What is the difference between a static (instance)
// method and a non-static (class) method?  Write the
// non-static method "raceAgainst" that behaves exactly like
// two-parameter method "race".  Look in the main method to
// see how many parameters raceAgainst must have.
// 
// (6) Is it true that any non-static method could be
// re-worked into a static method and vice versa?
// 
// (7) The "swapShoes" method in the Runner class swaps the
// shoes of two runners.  Add some code to the main method
// to swap the shoes of two runners and verify that the
// shoes do indeed get swapped.
// 
// (8) Write a method called "swapNames" that swaps
// the names of two runners.
// 
// (9) Write a method "swapSpeeds" that swaps the "speed"
// properties of two runners.
//