Solutions to the Try It Out Exercises in Beginning Programming with Java For Dummies, 5th Edition
by Barry Burd

Chapter 15: The Old Runaround

In this chapter:

• Narcissist’s code
• British pounds to US dollars
• Mystery code
• Draw a pattern
• Times table
• Do I hear an echo?
• Tally ho!
• Enumerate the possibilities
• Show your hands

Narcissist’s code

import java.util.Scanner;

public class Narcissist {
    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        String name;
        int howMany;
        
        System.out.print("What's your name? ");
        name = keyboard.nextLine();
        System.out.print("How many times would you like me to display your name? ");
        howMany = keyboard.nextInt();
        
        for (int i = 1; i <= howMany; i++) {
            System.out.println(name);
        }
        
        keyboard.close();
    }
}

British pounds to US dollars

public class PoundsToDollars {
    
    public static void main(String[] args) {
        
        System.out.println("Pounds   Dollars");
        
        for (int pounds = 1; pounds <= 9; pounds++) {
            System.out.print("  ");
            System.out.print(pounds);
            System.out.print("        ");
            System.out.println(pounds * 1.25);
        }
        
    }
}

Mystery code

*****
*****
*****
*****
*****

*
**
***
****
*****

Draw a pattern

import java.util.Scanner;

public class DrawPattern1 {
    
    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int howMany;
        
        howMany = keyboard.nextInt();
        
        for (int i = 1; i <= howMany; i++) {
            System.out.print("-");
        }
        System.out.println();
        
        keyboard.close();
    }
}

import java.util.Scanner;

public class DrawPattern2 {
    
    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int howMany;
        
        howMany = keyboard.nextInt();
        
        for (int i = 1; i <= howMany; i++) {
            System.out.print("-");
        }
        System.out.println();
        
        for (int i = 1; i <= howMany - 1; i++) {
            System.out.print("-");
        }
        System.out.println();
        
        keyboard.close();
    }
}

import java.util.Scanner;

public class DrawPattern3 {

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int howMany;

        howMany = keyboard.nextInt();

        for (int row = 1; row <= howMany; row++) {
            for (int i = 1; i <= howMany - row + 1; i++) {
                System.out.print("-");
            }
            System.out.println();
        }

        keyboard.close();
    }
}

import java.util.Scanner;

public class DrawPattern4 {

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int howMany;

        howMany = keyboard.nextInt();

        for (int row = 1; row <= howMany; row++) {
            for (int i = 1; i <= howMany - row; i++) {
                System.out.print("-");
            }
            System.out.println("/");
        }

        keyboard.close();
    }
}

Times table

public class TimesTable1 {

    public static void main(String[] args) {
        for (int i = 1; i <= 9; i++) {
            System.out.print(i);
            System.out.print("\t");
        }
    }

}

public class TimesTable2 {

    public static void main(String[] args) {
        for (int i = 1; i <= 9; i++) {
            System.out.print(2 * i);
            System.out.print("\t");
        }
    }

}

public class TimesTable3 {

    public static void main(String[] args) {
        for (int row = 1; row <= 9; row++) {
            for (int i = 1; i <= 9; i++) {
                System.out.print(row * i);
                System.out.print("\t");
            }
            System.out.println();
        }
    }

}

public class TimesTable4 {

    public static void main(String[] args) {

        for (int i = 1; i <= 9; i++) {
            System.out.print("\t");
            System.out.print(i);
        }
        System.out.println();

        System.out.print("\t");
        System.out.println("------------------------------------------------------------------");

        for (int row = 1; row <= 9; row++) {
            System.out.print(row);
            System.out.print("     |");
            for (int i = 1; i <= 9; i++) {
                System.out.print("\t");
                System.out.print(row * i);
            }
            System.out.println();
        }
    }

}

Do I hear an echo?

import java.util.Scanner;

public class Echo {

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int number;
        char reply;

        do {
            System.out.print("Enter a number: ");
            number = keyboard.nextInt();
            System.out.println(number);
            System.out.print("Continue? (y/n) ");
            reply = keyboard.findWithinHorizon(".", 0).charAt(0);
            System.out.println();
        } while (reply != 'n');

        System.out.println("Done!");
        
        keyboard.close();
    }

}

Tally ho!

import java.util.Scanner;

public class Tally {

    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        int number, sum = 0;

        do {
            System.out.print("Enter a non-zero number, or zero to quit: ");
            number = keyboard.nextInt();
            sum += number;
        } while (number != 0);

        System.out.println(sum);

        keyboard.close();
    }

}

Enumerate the possibilities

public class Possibilities {

    enum Hand {
        paper, scissors, stone
    }

    public static void main(String[] args) {
        for (Hand hand : Hand.values()) {
            System.out.println(hand);
        }
    }

}

Show your hands

public class ShowYourHands {

    enum Hand {
        paper, scissors, stone
    }

    public static void main(String[] args) {
        for (Hand hand1 : Hand.values()) {
            for (Hand hand2 : Hand.values()) {
                System.out.print(hand1);
                System.out.print(" ");
                System.out.println(hand2);
            }
        }
    }

}