1 / 63

Starting Out with Java: From Control Structures through Objects 5 th edition By Tony Gaddis

Starting Out with Java: From Control Structures through Objects 5 th edition By Tony Gaddis Source Code: Chapter 6. Code Listing 6-1 (ObjectDemo.java) 1 import java.util.Scanner; // Needed for the Scanner class 2 import java.util.Random; // Needed for the Random class

twhittle
Download Presentation

Starting Out with Java: From Control Structures through Objects 5 th edition By Tony Gaddis

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Starting Out with Java:From Control Structures through Objects • 5th edition • By Tony Gaddis • Source Code: Chapter 6

  2. Code Listing 6-1 (ObjectDemo.java) 1 import java.util.Scanner; // Needed for the Scanner class 2 import java.util.Random; // Needed for the Random class 3 import java.io.*; // Needed for file I/O classes 4 5 /* 6 This program writes random numbers to a file. 7 */ 8 9 public class ObjectDemo 10 { 11 public static void main(String[] args) throws IOException 12 { 13 int maxNumbers; // Max number of random numbers 14 int number; // To hold a random number 15 16 // Create a Scanner object for keyboard input. 17 Scanner keyboard = new Scanner(System.in); 18 19 // Create a Random object to generate random numbers. 20 Random rand = new Random(); 21 22 23 PrintWriter outputFile= new PrintWriter("numbers.txt"); (Continued)

  3. 24 25 // Get the number of random numbers to write. 26 System.out.print("How many random numbers should I write? "); 27 maxNumbers = keyboard.nextInt(); 28 29 // Write the random numbers to the file. 30 for (int count = 0; count < maxNumbers; count++) 31 { 32 33 number = rand.nextInt(); 34 • // Write the random integer to the file. 36 outputFile.println(number); 37 } 38 39 // Close the file. 40 outputFile.close(); 41 System.out.println("Done"); 42 } 43 } Program Output with Example Input Shown in Bold How many random numbers should I write? 10 [ Enter] Done

  4. Code Listing 6-2 (Rectangle.java) 1 /** 2 Rectangle class, phase 1 3 Under construction! 4 */ 5 6 public class Rectangle 7 { 8 private double length; 9 privatedouble width; 10 11 /** 12 The setLength method stores a value in the 13 length field. 14 @param len The value to store in length. 15 */ 16 17 public void setLength( double len ) 18 { 19 length = len; 20 } 21 }

  5. Code Listing 6-3 (LengthDemo.java) 1 /** 2 This program demonstrates the Rectangle class's 3 setLength method. 4 */ 5 6 public class LengthDemo 7 { 8 public static void main(String[] args) 9 { 10 // Create a Rectangle object. 12 Rectangle box = new Rectangle(); // Constructor method? 13 14 15 System.out.println("Sending the value 10.0 " + 16 "to the setLength method."); 17 • // Call the box object's setLength method. 19 box.setLength(10.0); (Continued)

  6. 20 • // Indicate we are done. 22 System.out.println("Done."); 23 } // end main 24 } // end class Program Output Sending the value 10.0 to the setLength method. Done.

  7. Code Listing 6-4 (Rectangle.java) 1 /** 2 Rectangle class, phase 2 3 Under construction! 4 */ 5 6 public class Rectangle 7 { 8 private double length; 9 private double width; 10 11 /** 12 The setLength method stores a value in the 13 length field. 14 @param len The value to store in length. 15 */ 16 17 public void setLength( double len ) 18 { 19 length = len; 20 } 21 (Continued)

  8. 22 /** 23 The setWidth method stores a value in the 24 width field. 25 @param w The value to store in width. 26 */ 27 28 public void setWidth(double w) 29 { 30 width = w; 31 } 32 }

  9. Code Listing 6-5 (Rectangle.java) 1 /** 2 Rectangle class, phase 3 3 Under construction ! 4 */ 5 6 public class Rectangle 7 { 8 private double length; 9 private double width; 10 11 /** 12 The setLength method stores a value in the 13 length field. 14 @param len The value to store in length. 15 */ 16 17 public void setLength(double len) 18 { 19 length = len; 20 } 21 (Continued)

  10. 22 /** 23 The setWidth method stores a value in the 24 width field. 25 @param w The value to store in width. 26 */ 27 28 public void setWidth(double w) 29 { 30 width = w; 31 } 32 33 /** 34 The getLength method returns a Rectangle 35 object's length. 36 @return The value in the length field. 37 */ 38 39 public double getLength() 40 { 41 returnlength; 42 } 43 (Continued)

  11. 44 /** 45 The getWidth method returns a Rectangle 46 object's width. 47 @return The value in the width field. 48 */ 49 50 public double getWidth() 51 { 52 returnwidth; 53 } 54 }

  12. Code Listing 6-6 (LengthWidthDemo.java) 1 /** 2 This program demonstrates the Rectangle class's 3 setLength, setWidth, getLength, and getWidth methods. 4 */ 5 6 public class LengthWidthDemo 7 { 8 public static void main(String[] args) 9 { 10 // Create a Rectangle object. 11 Rectangle box = new Rectangle(); 12 13 // Call the object's setLength method, passing 10.0 14 // as an argument. 15 box.setLength(10.0); 16 17 // Call the object's setWidth method, passing 20.0 18 // as an argument. 19 box.setWidth(20.0); 20 (Continued)

  13. // Display the object's length and width. 22 System.out.println("The box's length is " + 23 box.getLength()); 24 System.out.println("The box's width is " + 25 box.getWidth()); 26 } 27 } Program Output The box's length is 10.0 The box's width is 20.0

  14. Code Listing 6-7 (Rectangle.java) 1 /** 2 Rectangle class, phase 4 3 Under construction! 4 */ 5 6 public class Rectangle 7 { 8 private double length; 9 private double width; 10 11 /** 12 The setLength method stores a value in the 13 length field. 14 @param len The value to store in length. 15 */ 16 17 public void setLength( double len ) 18 { 19 length = len; 20 } 21 (Continued)

  15. 22 /** 23 The setWidth method stores a value in the 24 width field. 25 @param w The value to store in width. 26 */ 27 28 public void setWidth( double w ) 29 { 30 width = w; 31 } 32 33 /** 34 The getLength method returns a Rectangle 35 object's length. 36 @return The value in the length field. 37 */ 38 39 public double getLength() 40 { 41 returnlength; 42 } 43 (Continued)

  16. 44 /** 45 The getWidthmethod returns a Rectangle 46 object's width. 47 @return The value in the width field. 48 */ 49 50 public double getWidth() 51 { 52 return width; 53 } 54 55 /** 56 The getArea method returns a Rectangle 57 object's area. 58 @return The product of length times width. 59 */ 60 61 public double getArea() // What is Stale data? 62 { 63 returnlength *width; 64 } 65 }

  17. Code Listing 6-8 (RectangleDemo.java) 1 /** 2 This program demonstrates the Rectangle class's 3 setLength, setWidth, getLength, getWidth, and 4 getArea methods. 5 */ 6 7 public class RectangleDemo 8 { 9 public static void main(String[] args) 10 { • // Create a Rectangle object. 12 Rectanglebox = newRectangle(); 13 15 box.setLength(10.0); 16 box.setWidth(20.0); 17 • // Display the length. 19 System.out.println("The box's length is " + 20 box.getLength()); (Continued)

  18. 21 • // Display the width. 23 System.out.println("The box's width is " + 24 box.getWidth()); 25 • // Display the area. 27 System.out.println("The box's area is " + 28 box.getArea()); 29 } 30 } Program Output The box's length is 10.0 The box's width is 20.0 The box's area is 200.0

  19. Code Listing 6-9 (RoomAreas.java) 1 import javax.swing.JOptionPane; 2 3 /** 4 This program creates three instances of the 5 Rectangle class. 6 */ 7 8 public class RoomAreas 9 { 10 public static void main(String[] args) 11 { 12 double number; // To hold a number 13 double totalArea; // The total area 14 String input; // To hold user input 15 16 // Create three Rectangle objects. 17 Rectangle kitchen = new Rectangle(); 18 Rectangle bedroom = new Rectangle(); 19 Rectangle den = new Rectangle(); 20 (Continued)

  20. 22 input = JOptionPane.showInputDialog("What is the " + 23 "kitchen's length?"); 24 number = Double.parseDouble(input); • kitchen.setLength(number); 26 input = JOptionPane.showInputDialog("What is the " + 27 "kitchen's width?"); 28 number = Double.parseDouble(input); • kitchen.setWidth(number); 30 • // Get and store the dimensions of the bedroom. 32 input = JOptionPane.showInputDialog("What is the " + 33 "bedroom's length?"); 34 number = Double.parseDouble(input); • bedroom.setLength(number); 36 input = JOptionPane.showInputDialog("What is the " + 37 "bedroom's width?"); 38 number = Double.parseDouble(input); 39 bedroom.setWidth(number); 40 (Continued)

  21. 42 input = JOptionPane.showInputDialog("What is the " + 43 "den's length?"); 44 number = Double.parseDouble(input); 45 den.setLength(number); 46 input = JOptionPane.showInputDialog("What is the " + 47 "den's width?"); 48 number = Double.parseDouble(input); 49 den.setWidth(number); 52 totalArea = kitchen.getArea() + bedroom.getArea() 53 + den.getArea(); 54 56 JOptionPane.showMessageDialog(null, " + "The total area” + 57 "of the rooms is " + totalArea); 58 59 System.exit(0); 60 } 61 }

  22. Code Listing 6-10 (Rectangle.java) 1 /** 2 Rectangle class, phase 5 3 */ 4 5 public class Rectangle 6 { 7 private double length; 8 private double width; 9 10 /** 11 Constructor 12 @param len The length of the rectangle. 13 @param w The width of the rectangle. 14 */ 15 16 public Rectangle( double len, double w ) 17 { 18 length = len; 19 width = w; • } . . . The remainder of the class has not changed, and is not shown.

  23. Code Listing 6-11 (ConstructorDemo.java) 1 /** 2 This program demonstrates the Rectangle class's 3 constructor. 4 */ 5 6 public class ConstructorDemo 7 { 8 public static voidmain(String[] args) 9 { 10 // Create a Rectangle object, passing 5.0 and • // 15.0 as arguments to the constructor. 12 Rectanglebox = new Rectangle( 5.0, 15.0 ); 13 14 // Display the length. 15 System.out.println("The box's length is " + 16 box.getLength()); 17 18 // Display the width. 19 System.out.println("The box's width is " + 20 box.getWidth()); 21 (Continued)

  24. 22 // Display the area. 23 System.out.println("The box's area is " + 24 box.getArea()); 25 } 26 } Program Output The box's length is 5.0 The box's width is 15.0 The box's area is 75.0

  25. Code Listing 6-12 (CellPhone.java) 1 /** 2 The CellPhone class holds data about a cell phone. 3 */ 4 5 public class CellPhone 6 { 7 // Fields 8 private String manufact; // Manufacturer 9 private String model; // Model 10 private double retailPrice; // Retail price 11 12 /** 13 Constructor 14 @param man The phone's manufacturer. 15 @param mod The phone's model number. 16 @param price The phone's retail price. 17 */ 18 19 public CellPhone( String man, String mod, double price ) 20 { 21manufact = man; 22 model = mod; 23 retailPrice = price; (Continued)

  26. 24 } 25 26 /** 27 The setManufact method sets the phone's 28 manufacturer name. 29 @param man The phone's manufacturer. 30 */ 31 32 public void setManufact( String man ) 33 { 34 manufact = man; 35 } 36 37 /** 38 The setMod method sets the phone's 39 model number. 40 @param mod The phone's model number. 41 */ 42 43 public void setMod( String mod ) 44 { 45 model = mod; 46 } (Continued)

  27. 47 48 /** 49 The setRetailPrice method sets the phone's 50 retail price. 51 @param price The phone's retail price. 52 */ 53 54 public void setRetailPrice( double price ) 55 { 56 retailPrice = price; 57 } 58 59 /** 60 getManufact method 61 @return The name of the phone's manufacturer. 62 */ 63 64 public String getManufact() 65 { 66 returnmanufact; 67 } 68 (Continued)

  28. 69 /** 70 getModel method 71 @return The phone's model number. 72 */ 73 74 public String getModel() 75 { 76 returnmodel; 77 } 78 79 /** 80 getretailPrice method 81 @return The phone's retail price. 82 */ 83 84 public double getRetailPrice() 85 { 86 return retailPrice; 87 } 88 }

  29. Code Listing 6-13 (CellPhoneTest.java) 1 import java.util.Scanner; 2 3 /** 4 This program runs a simple test 5 of the CellPhone class. 6 */ 7 8 public class CellPhoneTest 9 { 10 public static voidmain(String[] args) 11 { 12 String testMan;// To hold a manufacturer 13 String testMod;// To hold a model number 14 double testPrice;// To hold a price 15 16 // Create a Scanner object for keyboard input. 17 Scanner keyboard = new Scanner(System.in); 18 19 // Get the manufacturer name. 20 System.out.print("Enter the manufacturer: "); 21 testMan = keyboard.nextLine(); 22 (Continued)

  30. 23 // Get the model number. 24 System.out.print("Enter the model number: "); 25 testMod = keyboard.nextLine(); 26 27 // Get the retail price. 28 System.out.print("Enter the retail price: "); • testPrice = keyboard.nextDouble(); 30 // Create an instance of the CellPhone class, 31 32 34 CellPhonephone =newCellPhone( testMan, testMod, testPrice ); 35 36 // Get the data from the phone and display it. 37 System.out.println(); 38 System.out.println("Here is the data that you provided:"); 39 System.out.println("Manufacturer: " + phone.getManufact()); 40 System.out.println("Model number: " + phone.getModel()); 41 System.out.println("Retail price: " + phone.getRetailPrice()); 42 } 43 } (Continued)

  31. Program Output with Example Input Shown in Bold Enter the manufacturer: Acme Electronics [ Enter ] Enter the model number: M1000 [ Enter ] Enter the retail price: 199.99 [ Enter ] Here is the data that you provided: Manufacturer: Acme Electronics Model number: M1000 Retail price: $199.99

  32. Code Listing 6-14 (Die.java) 1 import java.util.Random; 2 3 /** 4 The Die class simulates a six-sided die. 5 */ 6 7 public class Die 8 { 9 private int sides; // Number of sides 10 private int value; // The die's value 11 12 /** 13 The constructorperforms an initial 14 roll of the die. 15 @param numSides The number of sides for this die. 16 */ 17 18publicDie( int numSides ) 19 { 20 sides = numSides; 21 roll(); // What are we calling? 22 } 23 (Continued)

  33. 24 /** 25 The roll method simulates the rolling of 26 the die. 27 */ 28 29 public void roll() 30 { 31 // Create a Random object. 32 Random rand = new Random(); 33 34 // Get a random value for the die. 35 value= rand.nextInt(sides) + 1; // What is value? 36 } 37 38 /** 39 getSides method 40 @return The number of sides for this die. 41 */ 42 43 public int getSides() 44 { 45 returnsides; // What is sides? 46 } (Continued)

  34. 47 48 /** 49 getValue method 50 @return The value of the die. 51 */ 52 53 public int getValue() 54 { 55 returnvalue; 56 } 57 } End Class

  35. Code Listing 6-15 (DiceDemo.java) 1 /** 2 This program simulates the rolling of dice. 3 */ 4 5 public class DiceDemo 6 { 7 public static void main(String[] args) 8 { 9 final int DIE1_SIDES = 6; // Number of sides for die #1 10 final int DIE2_SIDES = 12; // Number of sides for die #2 11 final int MAX_ROLLS = 5; // Number of times to roll 12 13 // Create two instances of the Die class. 14 Die die1 = new Die(DIE1_SIDES); 15 Die die2 = new Die(DIE2_SIDES); 16 17 // Display the initial state of the dice. 18 System.out.println("This simulates the rolling of a " + 19 DIE1_SIDES + " sided die and a " + 20 DIE2_SIDES + " sided die."); 21 22 System.out.println("Initial value of the dice:"); 23 System.out.println( die1.getValue() + " " + die2.getValue() ); (Continued)

  36. 24 • // Roll the dice five times. 26 System.out.println("Rolling the dice " + MAX_ROLLS + " times."); 27 28 for (int i = 0; i < MAX_ROLLS; i++) 29 { 30 // Roll the dice. 31 die1.roll(); 32 die2.roll(); 33 34 // Display the values of the dice. 35 System.out.println(die1.getValue() + " " + die2.getValue() ); 36 } 37 } 38 } Program Output This simulates the rolling of a 6 sided die and a 12 sided die. Initial value of the dice: 2 7 Rolling the dice 5 times. 3 5 5 2 2 1 4 1 5 9

  37. Code Listing 6-16 (DieArgument.java) 1 /** 2 This program rolls a 6-sided die and 3a 20-sided die. 4 */ 5 6 public class DieArgument 7 { 8 public static void main(String[] args) 9 { 10 final int SIX_SIDES = 6; 11 final int TWENTY_SIDES = 20; 12 13 14 DiesixDie = new Die(SIX_SIDES); 15 16 17 DietwentyDie = new Die(TWENTY_SIDES); 18 • // Roll the dice. 20 rollDie(sixDie); 21 rollDie(twentyDie); // Passing a Reference as an Argument 22 } (Continued)

  38. 23 24 /** 25 This method simulates a die roll, displaying 26 the die's number of sides and value. 27 @param d The Die object to roll. 28 */ 29 30 public static void rollDie(Die d) // Receiving the Reference Argument 31 { 32 // Display the number of sides. 33 System.out.println("Rolling a " + d.getSides() + 34 " sided die."); 35 36 // Roll the die. 37 d.roll(); 38 39 // Display the die's value. 40 System.out.println("The die's value: " +d.getValue()); 41 } 42 } Program Output Rolling a 6 sided die. The die's value: 3 Rolling a 20 sided die. The die's value: 19

  39. Code Listing 6-17 (Dealer.java) 1 /** 2 Dealer class for the game of Cho-Han( Uses Die class ) 3 */ 4 5 public class Dealer 6 { 7 private int die1Value; // The value of die #1 8 private int die2Value; // The value of die #2 9 10 /** 11 Constructor 12 */ 13 14 public Dealer() 15 { 16 die1Value = 0; 17 die2Value = 0; 18 } 19 20 /** 21 The rollDice method rolls the dice and saves 22 their values. 23 */ (Continued)

  40. 24 25 public void rollDice() 26 { 27 final int SIDES = 6; // Number of sides for the dice 28 29 // Create the two dice. (This also rolls them.) 30 Die die1 = new Die(SIDES); 31 Die die2 = new Die(SIDES); 32 33 34 die1Value = die1.getValue(); // Where is memory for die1Value 35 die2Value = die2.getValue(); // and die2Value allocated? 36 } 37 38 /** 39 The getChoOrHan method returns the result of 40 the dice roll, Cho or Han. 41 @return Either "Cho (even)" or "Han (odd)" 42 */ 43 44 public StringgetChoOrHan() 45 { 46 String result; // To hold the result (Continued)

  41. 47 48 // Get the sum of the dice. 49 int sum = die1Value + die2Value; 50 51 // Determine even or odd. 52 if (sum % 2 == 0) 53 result = "Cho (even)"; 54 else 55 result = "Han (odd)"; 56 57 // Return the result. 58 return result; 59 } 60 61 /** 62 The getDie1Value method returns the value of 63 die #1. 64 @return The die1Value field 65 */ 66 (Continued)

  42. 67 public int getDie1Value() 68 { 69 return die1Value; 70 } 71 72 /** 73 The getDie2Value method returns the value of 74 die #2. 75 @return The die2Value field 76 */ 77 78 public int getDie2Value() 79 { 80 return die2Value; 81 } 82 }

  43. Code Listing 6-18 (Player.java) 1 import java.util.Random; 2 3 /** 4 Player class for the game of Cho-Han 5 */ 6 7 public class Player 8 { 9 private String name; // The player's name 10 private String guess; // The player's guess 11 private int points; // The player's points 12 13 /** 14 Constructor 15 @param playerName The player's name. 16 */ 17 18 public Player(String playerName) 19 { 20 name = playerName; 21 guess = ""; 22 points = 0; 23 } (Continued)

  44. 24 25 /** 26 The makeGuess method causes the player to guess 27 either "Cho (even)" or "Han (odd)". 28 */ 29 30 public void makeGuess() 31 { 33 Random rand = new Random(); 34 36 int guessNumber = rand.nextInt(2); 37 38 // Convert the random number to a guess of • // either "Cho (even)" or "Han (odd)". 40 if(guessNumber == 0) 41 guess = "Cho (even)"; 42 else 43 guess = "Han (odd)"; 44 } 45 (Continued)

  45. 46 /** 47 The addPoints method adds a specified number of 48 points to the player's current balance. 49 @newPoints The points to add. 50 */ 51 52 public void addPoints(int newPoints) 53 { 54 points += newPoints; 55 } 56 57 /** 58 The getName method returns the player's name. 59 @return The value of the name field. 60 */ 61 62 public String getName() 63 { 64 return name; 65 } 66 (Continued)

  46. 67 /** 68 The getGuess method returns the player's guess. 69 @return The value of the guess field. 70 */ 71 72 public String getGuess() 73 { 74 return guess; 75 } 76 77 /** 78 The getPoints method returns the player's points 79 @return The value of the points field. 80 */ 81 82 public int getPoints() 83 { 84 return points; 85 } 86 }

  47. Code Listing 6-19 (ChoHan.java) 1 import java.util.Scanner; 2 3 public class ChoHan 4 { 5 public static void main(String[] args) 6 { 7 final int MAX_ROUNDS = 5; // Number of rounds 8 String player1Name; // First player's name 9 String player2Name; // Second player's name 10 11 12 Scanner keyboard = new Scanner(System.in); 13 15 System.out.print("Enter the first player's name: "); • player1Name = keyboard.nextLine(); 17 System.out.print("Enter the second player's name: "); 18 player2Name = keyboard.nextLine(); 19 20 // Create the dealer. 21 Dealer dealer = new Dealer(); 22 (Continued)

  48. 23 // Create the two players. 24 Player player1 = new Player(player1Name); 25 Player player2 = new Player(player2Name); 26 27 // Play the rounds. 28 for (int round = 0; round < MAX_ROUNDS; round++) 29 { 30 System.out.println("----------------------------"); 31 System.out.printf("Now playing round %d.\n", round + 1); 32 33 // Roll the dice. 34 dealer.rollDice(); 35 36 // The players make their guesses. 37 player1.makeGuess(); 38 player2.makeGuess(); 39 40 // Determine the winner of this round. 41 roundResults( dealer, player1, player2 ); 42 } 43 • // Display the grand winner. 45 displayGrandWinner( player1, player2 ); (Continued)

  49. 46 } End Main 47 48 /** 49 The roundResults method determines the results of 50 the current round. 51 @param dealer The Dealer object 52 @param player1 Player #1 object 53 @param player2 Player #2 object 54 */ 55 56 public static void roundResults( Dealer dealer, Player player1, 57 Player player2 ) 58 { 59 // Show the dice values. 60 System.out.printf("The dealer rolled %d and %d.\n", 61 dealer.getDie1Value(), dealer.getDie2Value()); 62 System.out.printf("Result: %s\n", dealer.getChoOrHan() ); 63 64 // Check each player's guess and award points. 65 checkGuess( player1, dealer); 66 checkGuess( player2, dealer); 67 } (Continued)

  50. 68 69 /** 70 The checkGuess method checks a player's guess against 71 the dealer's result. 72 @param player The Player object to check. 73 @param dealer The Dealer object. 74 */ 75 76 public static void checkGuess( Player player, Dealer dealer ) 77 { 78 final int POINTS_TO_ADD = 1; // Points to award winner 79 String guess = player.getGuess(); // Player's guess 80 String choHanResult = dealer.getChoOrHan(); // Cho or Han 81 82 // Display the player's guess. 83 System.out.printf("The player %s guessed %s.\n", 84 player.getName(), player.getGuess()); 85 • // Award points if the player guessed correctly. 87 if (guess.equalsIgnoreCase(choHanResult) ) (Continued)

More Related