Chingar Doc 4.0^® ~ Unit 4

4.1.6: Using the Rectangle Class

//RectangleTester.java

public class RectangleTester extends ConsoleProgram
{
   public void run()
   {
       // Create a rectangle with width 5 and height 12
       Rectangle rect = new Rectangle(5, 12);
       // Then print it out
       System.out.println(rect);
   }
}

//Rectangle.java

public class Rectangle
{
   private int width;
   private int height;
   
   public Rectangle(int rectWidth, int rectHeight)
   {
       width = rectWidth;
       height = rectHeight;
   }
   
   public int getArea()
   {
       return width * height;
   }
   
   public int getHeight()
   {
       return height;
   }
   
   public int getWidth()
   {
       return width;
   }
   
   public String toString()
   {
       return "Rectangle with width: " + width + " and height: " + height;
   }
}

 

4.1.7: Calling a Method

public class RectangleTester extends ConsoleProgram
{
   public void run()
   {
       // Create a rectangle with width 7 and height 14
       Rectangle rect = new Rectangle(7, 14);
       // Print out the height
       System.out.println(rect.getHeight());
       // Print out the width
       System.out.println(rect.getWidth());
       // Print out the area by calling the getArea method
       System.out.println(rect.getArea());
   }
}

 

public class Rectangle
{
   private int width;
   private int height;
   
   public Rectangle(int rectWidth, int rectHeight)
   {
       width = rectWidth;
       height = rectHeight;
   }
   
   public int getArea()
   {
       return width * height;
   }
   
   public int getHeight()
   {
       return height;
   }
   
   public int getWidth()
   {
       return width;
   }
   
   public String toString()
   {
       return "Rectangle with width: " + width + " and height: " + height;
   }
}

 

4.1.8: Using the Point Class

public class Point
{
   private int x;
   private int y;
   
   public Point(int xCoord, int yCoord)
   {
       x = xCoord;
       y = yCoord;
   }
   
   public void move(int dx, int dy)
   {
       x += dx;
       y += dy;
   }
   
   public String toString()
   {
       return x + ", " + y;
   }
}

 

public class PointTester extends ConsoleProgram
{
   public void run()
   {
       Point p = new Point(10, 5);
       System.out.println(p);
       p.move(3, 4);
       
       System.out.println(p);
       
       // Make a new point here at position (2, 4)
       Point p2 = new Point(2, 4);
       // Then print it out
       System.out.println(p2);
   }
}

 

4.1.9: Using the Student Class

public class StudentTester extends ConsoleProgram
{
   public void run()
   {
       Student alan = new Student("Alan", "Turing", 11);
       Student ada = new Student("Ada", "Lovelace", 12);
       // Add an entry for yourself here!
       Student studentName = new Student("First name", "Last name", 10);
       
       System.out.println(alan);
       System.out.println(ada);
       // Print out your student object
       System.out.println(studentName);
   }
}

 

 

public class Student
{
   private String firstName;
   private String lastName;
   private int gradeLevel;
   
   public Student(String fName, String lName, int grade)
   {
       firstName = fName;
       lastName = lName;
       gradeLevel = grade;
   }
   
   public String toString()
   {
       return firstName + " " + lastName + " is in grade: " + gradeLevel;
   }
}

 

4.2.5: Text Messages

public class TextMessage
{
   private String message;
   private String sender;
   private String receiver;
   
   public TextMessage(String from, String to, String theMessage)
   {
       sender = from;
       receiver = to;
       message = theMessage;
   }
   
   public String toString()
   {
       return sender + " texted " + receiver + ": " + message;
   }
}

 

 

public class Messages extends ConsoleProgram
{
   public void run()
   {
       // Your code here.
       TextMessage t1 = new TextMessage(
           "Bart", "Lisa", "Where are you?"
       );
       TextMessage t2 = new TextMessage(
           "Lisa", "Bart", "I'm at school!"  
       );
       // Create the two TextMessage objects and print them out.
       System.out.println(t1);
       System.out.println(t2);
   }
}

 

4.3.5: Coin Flips

import java.util.*;

public class Randomizer{

public static Random theInstance = null;

public Randomizer(){

}

public static Random getInstance(){
if(theInstance == null){
theInstance = new Random();
}
return theInstance;
}

public static boolean nextBoolean(){
return Randomizer.getInstance().nextBoolean();
}

public static boolean nextBoolean(double probability){
return Randomizer.nextDouble() < probability;
}

public static int nextInt(){
return Randomizer.getInstance().nextInt();
}

public static int nextInt(int n){
return Randomizer.getInstance().nextInt(n);
}

/* Return a nubmer between min and max, inclusive. */
public static int nextInt(int min, int max){
return min + Randomizer.nextInt(max - min + 1);
}

public static double nextDouble(){
return Randomizer.getInstance().nextDouble();
}

public static double nextDouble(double min, double max){
return min + (max - min) * Randomizer.nextDouble();
}


}

 

 

 

public class CoinFlips extends ConsoleProgram
{
   public static final int FLIPS = 100;
   
   public void run()
   {
       int heads = 0;
       int tails = 0;
       for(int i = 0; i < FLIPS; i++)
       {
           if(Randomizer.nextBoolean())
           {
               System.out.println("Heads");
               heads++;
           }
           else
           {
               System.out.println("Tails");
               tails++;
           }
       }
       
       System.out.println("Heads: " + heads);
       System.out.println("Tails: " + tails);
       System.out.println("% Heads: " + heads / (double)FLIPS);
       System.out.println("% Tails: " + tails / (double)FLIPS);

   }
}

 

4.3.6: Longest Streak

public class LongestStreak extends ConsoleProgram
{
   public static final int FLIPS = 100;
   
   public void run()
   {
       int longestStreak = 0;
       int curStreak = 0;
       for(int i = 0; i < FLIPS; i++)
       {
           Boolean flip = Randomizer.nextBoolean();
           
           if (flip)
           {
               System.out.println("Heads");
               curStreak++;
               if (curStreak > longestStreak)
               {
                   longestStreak = curStreak;
               }
           }
           else
           {
               System.out.println("Tails");
               curStreak = 0;
           }
       }
       System.out.println("Longest streak of heads: " + longestStreak);
   }
}

 

 

 

import java.util.*;

public class Randomizer{

public static Random theInstance = null;

public Randomizer(){

}

public static Random getInstance(){
if(theInstance == null){
theInstance = new Random();
}
return theInstance;
}

public static boolean nextBoolean(){
return Randomizer.getInstance().nextBoolean();
}

public static boolean nextBoolean(double probability){
return Randomizer.nextDouble() < probability;
}

public static int nextInt(){
return Randomizer.getInstance().nextInt();
}

public static int nextInt(int n){
return Randomizer.getInstance().nextInt(n);
}

/* Return a nubmer between min and max, inclusive. */
public static int nextInt(int min, int max){
return min + Randomizer.nextInt(max - min + 1);
}

public static double nextDouble(){
return Randomizer.getInstance().nextDouble();
}

public static double nextDouble(double min, double max){
return min + (max - min) * Randomizer.nextDouble();
}


}

 

4.3.8: How Far Away is…?

/*
* This class stores information about a location on Earth.  Locations are
* specified using latitude and longitude.  The class includes a method for
* computing the distance between two locations.
*
* This implementation is based off of the example from Stuart Reges at
* the University of Washington.
*/

public class GeoLocation
{
   // Earth radius in miles
   public static final double RADIUS = 3963.1676;  

   private double latitude;
   private double longitude;

   /**
    * Constructs a geo location object with given latitude and longitude
    */
   public GeoLocation(double theLatitude, double theLongitude)
   {
       latitude = theLatitude;
       longitude = theLongitude;
   }

   /**
    * Returns the latitude of this geo location
    */
   public double getLatitude()
   {
       return latitude;
   }

   /**
    * returns the longitude of this geo location
    */
   public double getLongitude()
   {
       return longitude;
   }

   // returns a string representation of this geo location
   public String toString()
   {
       return "latitude: " + latitude + ", longitude: " + longitude;
   }

   // returns the distance in miles between this geo location and the given
   // other geo location
   public double distanceFrom(GeoLocation other)
   {
       double lat1 = Math.toRadians(latitude);
       double long1 = Math.toRadians(longitude);
       double lat2 = Math.toRadians(other.latitude);
       double long2 = Math.toRadians(other.longitude);
       // apply the spherical law of cosines with a triangle composed of the
       // two locations and the north pole
       double theCos = Math.sin(lat1) * Math.sin(lat2) +
           Math.cos(lat1) * Math.cos(lat2) * Math.cos(long1 - long2);
       double arcLength = Math.acos(theCos);
       return arcLength * RADIUS;
   }
}

 

 

 

public class HowFarAway extends ConsoleProgram
{
   public void run()
   {
       double firstLat = readDouble("Enter the latitude of the starting location: ");
       double firstLong = readDouble("Enter the longitude of the starting location: ");
       double secondLat = readDouble("Enter the latitude of the ending location: ");
       double secondLong = readDouble("Enter the longitude of the ending location: ");
       
       GeoLocation firstLoc = new GeoLocation(firstLat,firstLong);
       GeoLocation secondLoc = new GeoLocation(secondLat,secondLong);
       
       double distance = firstLoc.distanceFrom(secondLoc);
       
       System.out.println("The distance is " + distance + " miles.");
   }
}

 

4.4.5: Triangle Class: Constructor

public class TriangleTester extends ConsoleProgram
{
   public void run()
   {
       // Write the Triangle constructor in the Triangle class
       // and test out creating new Triangle objects here!
       
       // For example:
       Triangle testTriangle = new Triangle(5, 3);
       System.out.println(testTriangle);
   }
}

 

 

public class Triangle
{
   private double height;
   private double width;
   
   public Triangle(double triWidth, double triHeight)
   {
       width = triWidth;
       height = triHeight;
   }
   
   public String toString()
   {
       return "Triangle with width: " + width + " and height: " + height;
   }
}

 

4.4.8: toString for Flowers

public class Flower
{

   private String name;
   private String color;
   private String genus;
   private String species;

   public Flower(String theName, String theColor, String theGenus, String theSpecies)
   {
       name = theName;
       color = theColor;
       genus = theGenus;
       species = theSpecies;
   }

   public String toString()
   {
       return color + " " + name + " (" + genus + " " + species + ")";
   }
}

 

 

 

 

public class FlowerTester extends ConsoleProgram
{
   public void run()
   {
       Flower foxglove = new Flower("Foxglove", "Red", "Digitalis", "obscura");
       System.out.println(foxglove);
   }
}

 

4.4.9: Instance Variables for Your Dog

public class Dog
{
   private String breed;
   private String name;

   public Dog(String theBreed, String theName)
   {
       breed = theBreed;
       name = theName;
   }
   
   public String toString()
   {
       return name + " is a " + breed;
   }
}

 

 

 

public class DogTester extends ConsoleProgram
{
   public void run()
   {
       Dog golden = new Dog("Golden Retriever", "Sammy");
       System.out.println(golden);
   }
}

 

4.4.10: Student GPA Field

public class StudentTester extends ConsoleProgram
{
   public void run()
   {
       Student alan = new Student("Alan", "Turing", 11, 3.5);
       Student ada = new Student("Ada", "Lovelace", 12, 3.8);
       
       System.out.println(alan);
       System.out.println(ada);
   }
}

 

 

 

public class Student
{
   private String firstName;
   private String lastName;
   private int gradeLevel;
   // Add your instance variable here.
   private double gpa;
   
   /**
    * This is a constructor.  A constructor is a method
    * that creates an object -- it creates an instance
    * of the class. What that means is it takes the input
    * parameters and sets the instance variables (or fields)
    * to the proper values.
    *
    * Check out StudentTester.java for an example of how to use
    * this constructor.
    */
   public Student(String fName, String lName, int grade, double gradePointAverage)
   {
       firstName = fName;
       lastName = lName;
       gradeLevel = grade;
       gpa = gradePointAverage;
   }
   
   /**
    * This is a toString for the Student class. It returns a String
    * representation of the object, which includes the fields
    * in that object.
    */
   public String toString()
   {
       return firstName + " " + lastName + " is in grade: " + gradeLevel + " and has GPA: " + gpa;
   }
}

 

4.4.12: Pizza Time!

public class Pizza
{
   private String type;
   private String toppings;
   private int size;
   
   public Pizza(String theType, String theToppings, int theSize)
   {
       type = theType;
       toppings = theToppings;
       size = theSize;
   }
   
   public String toString()
   {
       return size + " inch " + type + " pizza with " + toppings;
   }
}

 

 

 

public class PizzaTester extends ConsoleProgram
{
   public void run()
   {
       // Test your Pizza class here.
       Pizza pizza1 = new Pizza("Veggie", "Tomatoes, onions, olives", 12);
       Pizza pizza2 = new Pizza("Cheese", "Cheese", 15);
       Pizza pizza3 = new Pizza("Meat", "Pepperoni, sausage, bacon", 20);
       
       System.out.println(pizza1);
       System.out.println(pizza2);
       System.out.println(pizza3);
   }
}

 

⚠ 4.4.13: Fractions ⚠

public class FractionTester extends ConsoleProgram
{
   public void run()
   {
       // ⚠ Students can create their own tests here for their Fraction class
   }
}

 

 

 

 

public class Fraction
{
   private int numerator;
   private int denominator;
   
   public Fraction(int thisNumerator, int thisDenominator)
   {
       numerator = thisNumerator;
       denominator = thisDenominator;
   }
   
   public String toString()
   {
       return numerator + "/" + denominator;
   }
}

 

4.5.5: Writing getPerimeter()

public class RectangleTester extends ConsoleProgram
{
   public void run()
   {
       // Create and test Rectangle objects here!
   }
}

 

 

 

public class Rectangle
{
   private int width;
   private int height;
   
   public Rectangle(int rectWidth, int rectHeight)
   {
       width = rectWidth;
       height = rectHeight;
   }
   
   public int getArea()
   {
       return width * height;
   }    
   
   public int getPerimeter()
   {
       return 2 * width + 2 * height;
   }
   
   public int getHeight()
   {
       return height;
   }
   
   public int getWidth()
   {
       return width;
   }
   
   public String toString()
   {
       return "Rectangle with width: " + width + " and height: " + height;
   }
}

 

4.5.6: Honors Students

public class StudentTester extends ConsoleProgram
{
   public void run()
   {
       Student alan = new Student("Alan", "Turing", 11);
       alan.setGPA(3.5);
       Student ada = new Student("Ada", "Lovelace", 12);
       ada.setGPA(3.8);
       
       System.out.println(alan);
       System.out.println(ada);
       
       System.out.println(alan.isHonorsStudent());
   }
}

 

 

public class Student
{
   private String firstName;
   private String lastName;
   private int gradeLevel;
   private double gpa;

   /**
    * This is a constructor.  A constructor is a method
    * that creates an object -- it creates an instance
    * of the class. What that means is it takes the input
    * parameters and sets the instance variables (or fields)
    * to the proper values.
    *
    * Check out StudentTester.java for an example of how to use
    * this constructor.
    */
   public Student(String fName, String lName, int grade)
   {
       firstName = fName;
       lastName = lName;
       gradeLevel = grade;
   }
   
   // This is a setter method to set the GPA for the Student.
   public void setGPA(double theGPA)
   {
       gpa = theGPA;
   }
   
   public boolean isHonorsStudent()
   {
       return gpa >= 3.5;
   }
   
   /**
    * This is a toString for the Student class. It returns a String
    * representation of the object, which includes the fields
    * in that object.
    */
   public String toString()
   {
       return firstName + " " + lastName + " is in grade: " + gradeLevel;
   }
}

 

4.5.7: The Full Triangle Class

public class TriangleTester extends ConsoleProgram
{
   public void run()
   {
       // Create and test out Triangle objects here!
   }
}

 

 

public class Triangle
{
   private int height;
   private int width;
   
   public Triangle(int triWidth, int triHeight)
   {
       width = triWidth;
       height = triHeight;
   }
   
   public int getHeight()
   {
       return height;
   }
   
   public int getWidth()
   {
       return width;
   }
   
   public double getArea()
   {
       return (.5 * width * height);
   }
}

 

4.5.8: Batting Average

public class BaseballTester extends ConsoleProgram
{
   public void run()
   {
       BaseballPlayer babeRuth = new BaseballPlayer("Babe Ruth", 2873, 8399);
       System.out.println(babeRuth);
       System.out.println(babeRuth.getBattingAverage());
   }
}

 

 

public class BaseballPlayer
{
   private int hits;
   private int atBats;
   private String name;
   
   public BaseballPlayer(String theName, int theHits, int theAtBats)
   {
       name = theName;
       hits = theHits;
       atBats = theAtBats;
   }
   
   public String toString()
   {
       return name + ": " + hits + "/" + atBats;
   }
   
   public double getBattingAverage()
   {
       return (double) hits / atBats;
   }
}

 

⚠ 4.5.9: Distance in Kilometers ⚠

/*
* This class stores information about a location on Earth.  Locations are
* specified using latitude and longitude.  The class includes a method for
* computing the distance between two locations.
*
* This implementation is based off of the example from Stuart Reges at
* the University of Washington.
*/

public class GeoLocation
{
   // Earth radius in miles
   public static final double RADIUS = 3963.1676;  
   
   // Number of kilomteres in one mile
   public static final double KM_PER_MILE = 1.60934;

   private double latitude;
   private double longitude;

   /**
    * Constructs a geo location object with given latitude and longitude
    */
   public GeoLocation(double theLatitude, double theLongitude)
   {
       latitude = theLatitude;
       longitude = theLongitude;
   }

   /**
    * Returns the latitude of this geo location
    */
   public double getLatitude()
   {
       return latitude;
   }

   /**
    * returns the longitude of this geo location
    */
   public double getLongitude()
   {
       return longitude;
   }

   // returns a string representation of this geo location
   public String toString()
   {
       return "latitude: " + latitude + ", longitude: " + longitude;
   }

   public double distanceFromInKilometers(GeoLocation other)
   {
       // fill this in.
       return distanceFrom(other) * KM_PER_MILE;
   }

   // returns the distance in miles between this geo location and the given
   // other geo location
   public double distanceFrom(GeoLocation other)
   {
       double lat1 = Math.toRadians(latitude);
       double long1 = Math.toRadians(longitude);
       double lat2 = Math.toRadians(other.latitude);
       double long2 = Math.toRadians(other.longitude);
       // apply the spherical law of cosines with a triangle composed of the
       // two locations and the north pole
       double theCos = Math.sin(lat1) * Math.sin(lat2) +
           Math.cos(lat1) * Math.cos(lat2) * Math.cos(long1 - long2);
       double arcLength = Math.acos(theCos);
       return arcLength * RADIUS;
   }
}

 

 

 

public class DistanceTester extends ConsoleProgram
{
   public static double SAN_FRANCISCO_LONGITUDE = 122.4167;
   public static double SAN_FRANCISCO_LATITUDE = 37.7833;
   public static double NEW_YORK_LONGITUDE = 74.0059;
   public static double NEW_YORK_LATITUDE = 40.7127;
   
   /**
    * This program computes the distance in miles between San Francisco, California
    * and New York City, New York using the GeoLocation class.
    *
    * After running this program, try looking it up on Google Maps. How close are we?
    */
   public void run()
   {
       GeoLocation sf = new GeoLocation(SAN_FRANCISCO_LATITUDE, SAN_FRANCISCO_LONGITUDE);
       GeoLocation nyc = new GeoLocation(NEW_YORK_LATITUDE, NEW_YORK_LONGITUDE);
       double distance = sf.distanceFromInKilometers(nyc);
       System.out.println("The distance from San Francisco to New York is " + distance + " kilometers");
   }
}

 

4.6.5: Text Messages Gather Methods

public class TextMessage
{
   private String message;
   private String sender;
   private String receiver;
   
   public TextMessage(String from, String to, String theMessage)
   {
       sender = from;
       receiver = to;
       message = theMessage;
   }
   
   public String getSender()
   {
       return sender;
   }
   
   public String getReceiver()
   {
       return receiver;
   }
   
   public String getMessage()
   {
       return message;
   }
   
   public String toString()
   {
       return sender + " texted " + receiver + ": " + message;
   }
}

 

 

public class Messages extends ConsoleProgram
{
   public void run()
   {
       // Your code here.
       // Create the two TextMessage objects and print them out.
       
       TextMessage message1 = new TextMessage("Ada", "Alan", "Hey! How is it going?");
       TextMessage message2 = new TextMessage("Alan", "Ada", "Pretty good how are you?");
       
       System.out.println(message1);
       System.out.println(message2);
   }
}

 

4.6.6: Fractions Getter/Setter Methods

public class FractionTester extends ConsoleProgram
{
   public void run()
   {
       // Add code here to test out your Fraction class!
   }
}

 

 

 

public class Fraction
{
   private int numerator;
   private int denominator;
   
   public Fraction(int num, int denom)
   {
       numerator = num;
       denominator = denom;
   }
   
   public int getNumerator()
   {
       return numerator;
   }
   
   public int getDenominator()
   {
       return denominator;
   }
   
   public void setNumerator(int x)
   {
       numerator = x;
   }
   
   public void setDenominator(int x)
   {
       denominator = x;
   }
   
   public String toString()
   {
       return numerator + "/" + denominator;
   }
}

 

4.6.7: Full Fraction Class

public class FractionTester extends ConsoleProgram
{
   public void run()
   {
       // Add code here to test out your Fraction class!
   }
}

 

 

public class Fraction
{
   private int numerator;
   private int denominator;

   public Fraction(int num, int denom) {
       numerator = num;
       denominator = denom;
   }

   public int getNumerator(){
       return this.numerator;
   }

   public int getDenominator(){
       return denominator;
   }

   public void add(Fraction other) {
       numerator = numerator * other.getDenominator() + other.getNumerator() * denominator;
       denominator = denominator * other.getDenominator();
   }

   public void subtract(Fraction other) {
       numerator = numerator * other.getDenominator() - other.getNumerator() * denominator;
       denominator = denominator * other.getDenominator();
   }

   public void multiply(Fraction other) {
       numerator = numerator * other.getNumerator();
       denominator = denominator * other.getDenominator();
   }

   public String toString() {
       return numerator + " / " + denominator;
   }
}

 

4.7.7: The Unit Circle

public class UnitCircle extends ConsoleProgram
{
   public void run()
   {
       System.out.println("Radians: (cos, sin)");
       for (double i = 0; i < 2*Math.PI; i += (Math.PI / 4))
       {
           double angle = Math.round(i * 100) / 100.0;
           double cos = Math.cos(angle);
           double sin = Math.sin(angle);
           cos = Math.round(cos * 100) / 100.0;
           sin = Math.round(sin * 100) / 100.0;
           String output = "" + angle + ": " + cos + ", " + sin;
           System.out.println(output);
       }
   }
}

 

4.7.8: How Many Players in the Game?

public class Player
{
   // Static Variables
   public static int totalPlayers = 0;
   public static int maxPlayers = 10;
   
   // Public Methods
   public Player()
   {
       totalPlayers++;
   }
   
   // Static Methods
   public static boolean gameFull()
   {
       return totalPlayers >= maxPlayers;
   }
}

 

4.7.9: Circle Area, another way

public class Circle
{
   private static final double PI = 3.14159265359;
   
   private double radius;
   
   public Circle(double theRadius)
   {
       radius = theRadius;
   }

   // Change the implementation of this method.
   public double getArea()
   {
       return PI * Math.pow(radius, 2);
   }
   
}

 

4.7.10: Rock, Paper, Scissors: Get Winner

private String getWinner(String user, String computer)
{
   String USER_PLAYER = "User wins!";
   String COMPUTER_PLAYER = "Computer wins!";
   String TIE = "Tie";

   if(user.equals(computer))
   {
       return TIE;
   }
   if(user.equals("rock") && computer.equals("paper"))
   {
       return COMPUTER_PLAYER;
   }
   if(user.equals("rock") && computer.equals("scissors"))
   {
       return USER_PLAYER;
   }
   if(user.equals("paper") && computer.equals("rock"))
   {
       return USER_PLAYER;
   }
   if(user.equals("paper") && computer.equals("scissors"))
   {
       return COMPUTER_PLAYER;    
   }
   if(user.equals("scissors") && computer.equals("rock"))
   {
       return COMPUTER_PLAYER;
   }
   return USER_PLAYER;
}

 

4.7.11: Rock, Paper, Scissors!

public class RockPaperScissors extends ConsoleProgram
{
   private static final String USER_PLAYER = "User wins!";
   private static final String COMPUTER_PLAYER = "Computer wins!";
   private static final String TIE = "Tie";
    
   /**
    * Function: getWinner
    *
    * Parameters:
    * String user - a string holding the choice that the user player
    * made. Must either be "rock", "paper", or "scissors"
    * String computer - a string holding the choice that the computer
    * player made. Must either be "rock", "paper", or "scissors"
    *
    * Determines the winner based on the rules of rock paper scissors.
    * Rock beats scissors and loses to paper
    * Paper beats rock and loses to scissors
    * Scissors beats paper and loses to rock
    * Identical choices tie
    *
    * Return: a string holding a message describing the winner, either
    * USER_PLAYER, COMPUTER_PLAYER, or TIE
    */
   private String getWinner(String user, String computer)
   {
       if(user.equals(computer))
       {
           return TIE;
       }
       if(user.equals("rock") && computer.equals("paper"))
       {
           return COMPUTER_PLAYER;
       }
       if(user.equals("rock") && computer.equals("scissors"))
       {
           return USER_PLAYER;
       }
       if(user.equals("paper") && computer.equals("rock"))
       {
           return USER_PLAYER;
       }
       if(user.equals("paper") && computer.equals("scissors"))
       {
           return COMPUTER_PLAYER;    
       }
       if(user.equals("scissors") && computer.equals("rock"))
       {
           return COMPUTER_PLAYER;
       }
       return USER_PLAYER;
   }
   
   public void run()
   {
       while(true){
           //Get the user's choice
           String choice = readLine("Enter your choice (rock, paper, or scissors): ");
           choice = choice.toLowerCase();
           
           //End the game if the user entered a blank line
           if(choice.equals("")){
               break;
           }
           
           //Make sure it was a valid choice
           if(choice.equals("rock") || choice.equals("paper") || choice.equals("scissors")){
               
               //Print the user choice
               System.out.println("User: " + choice);
           
               //Get the computer random choice
               String[] compChoices = new String[]{"rock", "paper", "scissors"};
               int compChoiceNum = Randomizer.nextInt(0, 2);
               String compChoice = compChoices[compChoiceNum];
               
               //Print the computer choice
               System.out.println("Computer: " + compChoice);
           
               //Print the winner
               System.out.println(getWinner(choice, compChoice));
           }
           else{
               System.out.println(choice + "is not a valid move. Please try again");
           }
       }
       
       //End the game with a nice message
       System.out.println("Thanks for playing!");
   }
}

 

4.8.5: Product Method Overloading

public class Product extends ConsoleProgram
{
   public void run()
   {
       int intValue = 5;
       double doubleValue = 2.5;
       
       int product1 = product(intValue, intValue);
       System.out.println(product1);
       
       // Use method overloading to define methods
       // for each of the following method calls
       
       double product2 = product(doubleValue, doubleValue);
       System.out.println(product2);
       
       int product3 = product(intValue, intValue, intValue);
       System.out.println(product3);
       
       double product4 = product(intValue, doubleValue);
       System.out.println(product4);
       
       double product5 = product(doubleValue, intValue);
       System.out.println(product5);
       
       double product6 = product(doubleValue, doubleValue, doubleValue);
       System.out.println(product6);
   }
   
   public int product(int one, int two)
   {
       return one * two;
   }
   
   public double product(double one, double two)
   {
       return one * two;
   }
   
   public int product(int one, int two, int three)
   {
       return one * two * three;
   }
   
   public double product(int one, double two)
   {
       return one * two;
   }
   
   public double product(double one, int two)
   {
       return one * two;
   }
   
   public double product(double one, double two, double three)
   {
       return one * two * three;
   }
}

 

4.9.6: Which Variables Exist?

public class MathOperations extends ConsoleProgram
{
   private double PI = 3.14159;
   
   public void run()
   {
       int sumResult = sum(5, 10);
       int differenceResult = difference(20, 2);
       double productResult = product(3.5, 2);
       double circumferenceResult = circleCircumference(10);
       double areaResult = circleArea(12);
   }
   
   public int sum(int one, int two)
   {
       // Printing Variables Example
       System.out.println("PI: " + PI);
       System.out.println("one: " + one);
       System.out.println("two: " + two);
       
       return one + two;
   }
   
   public int difference(int one, int two)
   {
       // PRINT OUT VARIABLES HERE
       System.out.println("PI: " + PI);
       System.out.println("one: " + one);
       System.out.println("two: " + two);
       
       return one - two;
   }
   
   public double product(double a, double b)
   {
       double result = a * b;
       
       // PRINT OUT VARIABLES HERE
       System.out.println("PI: " + PI);
       System.out.println("a: " + a);
       System.out.println("b: " + b);
       System.out.println("result: " + result);
       
       return result;
   }
   
   public double circleCircumference(int radius)
   {
       // PRINT OUT VARIABLES HERE
       System.out.println("PI: " + PI);
       System.out.println("radius: " + radius);
       
       return 2 * radius * PI;
   }
   
   public double circleArea(int radius)
   {
       double area = PI * radius * radius;
       
       // PRINT OUT VARIABLES HERE
       System.out.println("PI: " + PI);
       System.out.println("radius: " + radius);
       System.out.println("area: " + area);
       
       return area;
   }
}

 

4.10.4: Batteries - Needs to be Redone

public class BatteryTester extends ConsoleProgram
{
   public void run()
   {
       Battery aaBattery1 = new Battery(1.5);
       System.out.println("Total voltage: " + Battery.totalVoltage);
       System.out.println("Total batteries: " + Battery.numOfBatteries);
       
       Battery aaBattery2 = new Battery(1.5);
       System.out.println("Total voltage: " + Battery.totalVoltage);
       System.out.println("Total batteries: " + Battery.numOfBatteries);
       
       Battery aaBattery3 = new Battery(1.5);
       System.out.println("Total voltage: " + Battery.totalVoltage);
       System.out.println("Total batteries: " + Battery.numOfBatteries);
       
       Battery aaBattery4 = new Battery(1.5);
       System.out.println("Total voltage: " + Battery.totalVoltage);
       System.out.println("Total batteries: " + Battery.numOfBatteries);
       
   }
}

 

public class Battery
{
private double voltage;

public static double totalVoltage = 0;
public static int numOfBatteries = 0;

public Battery(double voltage)
{
this.voltage = voltage;

totalVoltage += voltage;
numOfBatteries += 1;
}

public double getVoltage()
{
return this.voltage;
}
}

4.10.5: Write Your Own CodeHS

public class ExerciseTester extends ConsoleProgram
{
   public void run()
   {
       Exercise exercise1 = new Exercise();
       Exercise exercise2 = new Exercise("Who needs this anyways?", "Java", 9001);
       
       System.out.println(exercise1.getTitle());
       System.out.println(exercise2.getTitle());
   }
}

 

 

public class Exercise
{
   public String title = "JavaScript Exercise";
   public String programmingLanguage = "JavaScript";
   public int points = 100;
   
   // Default constructor.
   public Exercise()
   {
       
   }
   
   // Edit code in this constructor.
   public Exercise(String title, String programmingLanguage, int points)
   {
       this.title = title;
       this.programmingLanguage = programmingLanguage;
       this.points =  points;
   }
   
   public String getTitle() {
       return title;
   }
}

 

4.11.7: Comparing Circles

public class CircleTester extends ConsoleProgram
{
   public void run()
   {
       Circle one = new Circle(10, "blue", 50, 35);
       Circle two = new Circle(10, "blue", 50, 35);
       Circle three = new Circle(20, "red", 0, 0);
       Circle four = three;
       
       if(one.equals(two))
       {
           System.out.println("Circles one and two are equal!");
           System.out.println(one);
           System.out.println(two);
       }
       
       if(three.equals(four))
       {
           System.out.println("Circles three and four are equal!");
           System.out.println(three);
           System.out.println(four);
       }
   }
}

 

public class Circle
{
   private int radius;
   private String color;
   private int x;
   private int y;
   
   public Circle(int theRadius, String theColor, int xPosition, int yPosition)
   {
       radius = theRadius;
       color = theColor;
       x = xPosition;
       y = yPosition;
   }
   
   public int getRadius()
   {
       return radius;
   }
   
   public int getX()
   {
       return x;
   }
   
   public int getY()
   {
       return y;
   }
   
   public String getColor()
   {
       return color;
   }
   
   public String toString()
   {
       return color + " circle with a radius of " + radius + " at position (" + x + ", " + y + ")";
   }
   
   public boolean equals(Circle other)
   {
       return color.equals(other.getColor()) && radius == other.getRadius() && x == other.getX() && y == other.getY();
   }
}

 

 

4.12.4: Clothing Store

public class TShirt extends Clothing
{
   private String fabric;

   public TShirt(String size, String color, String fabric)
   {
       super(size, color);
       this.fabric = fabric;
   }

   public String getFabric()
   {
       return fabric;
   }
}

 

 

public class ClothingTester extends ConsoleProgram
{
   public void run()
   {
       String size;
       String color;

       size = readLine("What size T-Shirt? ");
       color = readLine("What color is it? ");
       String fabric = readLine("What kind of fabric is it? ");
       TShirt tShirt = new TShirt(size, color, fabric);

       size = readLine("What size sweatshirt? ");
       color = readLine("What color is it? ");
       boolean hooded = readBoolean("Does it have a hood? ");
       Sweatshirt sweatShirt = new Sweatshirt(size, color, hooded);

       size = readLine("What size jeans? ");
       Jeans jeans = new Jeans(size);

       System.out.println("You want a " + tShirt.getSize() + " "
           + tShirt.getFabric() + " t-shirt in " + tShirt.getColor() + ".");
       if (sweatShirt.hasHood())
       {
           System.out.println("And a " + sweatShirt.getSize() + " "
               + sweatShirt.getColor() + " hooded sweatshirt.");
       } else {
           System.out.println("And a " + sweatShirt.getSize() + " "
               + sweatShirt.getColor() + " sweatshirt.");
       }
       System.out.println("Also, " + jeans.getSize() + " " + jeans.getColor()
           + " jeans.");
   }
}

 

 

public class Clothing
{
   private String size;
   private String color;

   public Clothing (String size, String color)
   {
       this.size = size;
       this.color = color;
   }

   public String getSize()
   {
       return size;
   }

   public String getColor()
   {
       return color;
   }
}

 

 

public class Sweatshirt extends Clothing
{
   private boolean hooded;

   public Sweatshirt(String size, String color, boolean hooded)
   {
       super(size, color);
       this.hooded = hooded;
   }

   public boolean hasHood()
   {
       return hooded;
   }
}

 

 

 

public class Jeans extends Clothing
{
   public Jeans(String size)
   {
       super(size, "blue");
   }
}

 

4.13.5: Finding the Perimeters

Note: Multi-tiered Section

public class Square extends Rectangle
{
   public Square(double sideLength)
   {
       super("Square", sideLength, sideLength);
   }
   
   public double getSideLength()
   {
       return super.getHeight();
   }
}

 

 

 

public abstract class Shape
{
   private String name;
   
   public Shape(String name)
   {
       this.name = name;
   }
   
   public void setName(String name)
   {
       this.name = name;
   }
   
   public String getName()
   {
       return this.name;
   }
   
   public abstract double getArea();
   
   public abstract double getPerimeter();

}

 

 

 

public class Rectangle extends Shape
{
   private double width;
   private double height;
   
   public Rectangle(String name, double width, double height)
   {
       super(name);
       this.width = width;
       this.height = height;
   }
   
   public Rectangle(double width, double height)
   {
       this("Rectangle", width, height);
   }
   
   public double getArea()
   {
       return width * height;
   }
   
   public double getPerimeter()
   {
       return 2 * (width + height);
   }
   
   public double getHeight()
   {
       return height;
   }
   
   public double getWidth()
   {
       return width;
   }
   
   public String toString()
   {
       return "Rectangle with width: " + width + " and height: " + height;
   }
}

 

 

 

public class ShapesTester extends ConsoleProgram
{
   public void run()
   {
       Shape rectangle = new Rectangle(10, 20);
       System.out.println("Name: " + rectangle.getName());
       System.out.println("Area: " + rectangle.getArea());
       System.out.println("Perimeter: " + rectangle.getPerimeter());
       System.out.println();

       Shape r2 = new Rectangle(5, 10);
       System.out.println("Name: " + r2.getName());
       System.out.println("Area: " + r2.getArea());
       System.out.println("Perimeter: " + r2.getPerimeter());
       System.out.println();

       Shape circle = new Circle(10);
       System.out.println("Name: " + circle.getName());
       System.out.println("Area: " + circle.getArea());
       System.out.println("Perimeter: " + circle.getPerimeter());
       System.out.println();

       Shape square = new Square(6);
       System.out.println("Name: " + square.getName());
       System.out.println("Area: " + square.getArea());
       System.out.println("Perimeter: " + square.getPerimeter());
       System.out.println();

       Shape pentagon = new Pentagon(5);
       System.out.println("Name: " + pentagon.getName());
       System.out.println("Area: " + pentagon.getArea());
       System.out.println("Perimeter: " + pentagon.getPerimeter());
       System.out.println();

   }
}

 

 

 

 

public class Pentagon extends Shape
{
   private double sideLength;

   public Pentagon(String name, double sideLength)
   {
       super(name);
       this.sideLength = sideLength;
   }

   public Pentagon(double sideLength)
   {
       this("Pentagon", sideLength);
   }

   public double getSideLength()
   {
       return sideLength;
   }

   public double getArea()
   {
       return 1.0 / 4.0 * Math.sqrt(5.0 * (5.0 + 2.0 * Math.sqrt(5.0)))
              * Math.pow(sideLength, 2);
   }

   public double getPerimeter()
   {
       return 5.0 * sideLength;
   }
}

 

 

 

public class Circle extends Shape
{
   private double radius;

   public Circle(String name, double radius)
   {
       super(name);
       this.radius = radius;
   }

   public Circle(double radius)
   {
       this("Circle", radius);
   }

   public double getRadius()
   {
       return radius;
   }

   public double getArea()
   {
       return Math.PI * Math.pow(radius, 2);
   }

   public double getPerimeter()
   {
       return 2.0 * Math.PI * radius;
   }
}

 

4.14.5: Fun with Solids

import java.lang.Math;

public class Pyramid extends Solid
{
   private double length;
   private double width;
   private double height;

   public Pyramid(String name, double l, double w, double h)
   {
       super(name);
       length = l;
       width = w;
       height = h;
   }

   public double volume()
   {
       return length * width * height / 3.0;
   }

   public double surfaceArea()
   {
       return length * width + length * Math.sqrt(Math.pow(width / 2.0, 2) +
           Math.pow(height, 2)) + width * Math.sqrt(Math.pow(length / 2.0, 2) +
           Math.pow(height, 2));
   }
}

 

 

import java.lang.Math;

public class Sphere extends Solid
{
   private double radius;

   public Sphere(String name, double radius)
   {
       super(name);
       this.radius = radius;
   }

   public double volume()
   {
       return (4.0/3.0) * Math.PI * Math.pow(this.radius, 3);
   }

   public double surfaceArea()
   {
       return 4.0 * Math.PI * Math.pow(this.radius, 2);
   }
}

 

 

 

public class RectangularPrism extends Solid
{
   private double length;
   private double width;
   private double height;

   public RectangularPrism(String name, double l, double w, double h)
   {
       super(name);
       length = l;
       width = w;
       height = h;
   }

   public double volume()
   {
       return length * width * height;
   }

   public double surfaceArea()
   {
       return 2 * (length * width + width * height + length * height);
   }
}

 

 

public abstract class Solid
{
   private String name;

   public Solid(String name)
   {
       this.name = name;
   }

   public String getName()
   {
       return name;
   }

   public abstract double volume();

   public abstract double surfaceArea();
}

 

public class SolidTester
{
   public static void main(String[] args)
   {
       String name;
       double volume;
       double surfaceArea;

       Pyramid pyramid = new Pyramid("My pyramid", 1, 3, 5);
       name = pyramid.getName();
       volume = round(pyramid.volume(), 2);
       surfaceArea = round(pyramid.surfaceArea(), 2);
       System.out.println("Pyramid '" + name + "' has volume: " + volume +
           " and surface area: " + surfaceArea + ".");

       Sphere sphere = new Sphere("My sphere", 4);
       name = sphere.getName();
       volume = round(sphere.volume(), 2);
       surfaceArea = round(sphere.surfaceArea(), 2);
       System.out.println("Sphere '" + name + "' has volume: " + volume +
           " and surface area: " + surfaceArea + ".");

       RectangularPrism rectangularPrism = new RectangularPrism("My rectangular prism",
           5, 8, 3);
       name = rectangularPrism.getName();
       volume = round(rectangularPrism.volume(), 2);
       surfaceArea = round(rectangularPrism.surfaceArea(), 2);
       System.out.println("RectangularPrism '" + name + "' has volume: " +
           volume + " and surface area: " + surfaceArea + ".");

       Cylinder cylinder = new Cylinder("My cylinder", 4, 9);
       name = cylinder.getName();
       volume = round(cylinder.volume(), 2);
       surfaceArea = round(cylinder.surfaceArea(), 2);
       System.out.println("Cylinder '" + name + "' has volume: " + volume +
           " and surface area: " + surfaceArea + ".");

       Cube cube = new Cube("My cube", 4);
       name = cube.getName();
       volume = round(cube.volume(), 2);
       surfaceArea = round(cube.surfaceArea(), 2);
       System.out.println("Cube '" + name + "' has volume: " + volume +
           " and surface area: " + surfaceArea + ".");
   }

   public static double round(double value, int places) {
       if (places < 0) throw new IllegalArgumentException();

       long factor = (long) Math.pow(10, places);
       value = value * factor;
       long tmp = Math.round(value);
       return (double) tmp / factor;
   }
}

 

 

public class Cube extends RectangularPrism
{
   public Cube(String name, double side)
   {
       super(name, side, side, side);
   }
}

 

 

import java.lang.Math;

public class Cylinder extends Solid
{
   private double radius;
   private double height;

   public Cylinder(String name, double radius, double height)
   {
       super(name);
       this.radius = radius;
       this.height = height;
   }

   public double volume()
   {
       return Math.PI * Math.pow(radius, 2) * height;
   }

   public double surfaceArea()
   {
       return 2 * Math.PI * radius * (radius + height);
   }
}

 

4.15.5: Fraction is Comparable

public class Fraction implements Comparable<Fraction>
{
   private int numerator;
   private int denominator;
   
   public Fraction(int numer, int denom)
   {
       numerator = numer;
       denominator = denom;
   }
   
   public void add(Fraction other)
   {
       numerator = numerator * other.getDenominator() +
                   other.getNumerator() * denominator;
       denominator *= other.getDenominator();
   }
   
   public void subtract(Fraction other)
   {
       numerator = numerator * other.getDenominator() -
                   other.getNumerator() * denominator;
       denominator *= other.getDenominator();
   }
   
   public void multiply(Fraction other)
   {
       numerator *= other.getNumerator();
       denominator *= other.getDenominator();
   }
   
   public int getNumerator()
   {
       return numerator;
   }
   
   public int getDenominator()
   {
       return denominator;
   }
   
   public void setNumerator(int x)
   {
       numerator = x;
   }
   
   public void setDenominator(int x)
   {
       denominator = x;
   }
   
   public String toString()
   {
       return numerator + "/" + denominator;
   }
   
   public int compareTo(Fraction other)
   {
       int diff = this.numerator * other.getDenominator() - other.getNumerator() * this.denominator;
       
       if(diff > 0)
       {
           return 1;
       }
       else if (diff < 0)
       {
           return -1;
       }
       else
       {
           return 0;
       }
   }
   
   public boolean equals(Object other)
   {
       return other instanceof Fraction && compareTo((Fraction)other) == 0;
   }
}

 

4.15.6: City is Summable

public class City implements Summable
{
   private int population;
   private String name;

   public City(String name, int population)
   {
       this.name = name;
       this.population = population;
   }

   public String getName()
   {
       return this.name;
   }

   public int getValue()
   {
       return this.population;
   }

   public int add(Summable other)
   {
       return getValue() + other.getValue();
   }
}