Do-While Loops

import java.util.Scanner;

public class DoWhileSwimming
{
    public static void main( String[] args ) throws Exception
    {
        Scanner keyboard = new Scanner(System.in);

        String swimmer1 = "GALLANT";
        String swimmer2 = "GOOFUS ";

        double minimumTemperature = 79.0; // degrees Fahrenheit
        double currentTemperature;
        double savedTemperature;
        int swimTime;

        System.out.print("What is the current water temperature? ");
        currentTemperature = keyboard.nextDouble();
        savedTemperature = currentTemperature; // saves a copy of this value so we can get it back later.

        System.out.println( "\nOkay, so the current water temperature is " + currentTemperature + "F." );
        System.out.println( swimmer1 + " approaches the lake...." );

        swimTime = 0;
        while ( currentTemperature >= minimumTemperature )
        {
            System.out.print( "\t" + swimmer1 + " swims for a bit." );
            swimTime++;
            System.out.println( " Swim time: " + swimTime + " min." );
            Thread.sleep(600); // pauses for 600 milliseconds
            currentTemperature -= 0.5; // subtracts 1/2 a degree from the water temperature
            System.out.println( "\tThe current water temperature is now " + currentTemperature + "F." );
        }

        System.out.println( swimmer1 + " stops swimming. Total swim time: " + swimTime + " min." );

        currentTemperature = savedTemperature; // restores original water temperature

        System.out.println( "\nOkay, so the current water temperature is " + currentTemperature + "F." );
        System.out.println( swimmer2 + " approaches the lake...." );

        swimTime = 0;
        do
        {
            System.out.print( "\t" + swimmer2 + " swims for a bit." );
            swimTime++;
            System.out.println( " Swim time: " + swimTime + " min." );
            Thread.sleep(600);
            currentTemperature -= 0.5;
            System.out.println( "\tThe current water temperature is now " + currentTemperature + "F." );

        } while ( currentTemperature >= minimumTemperature );

        System.out.println( swimmer2 + " stops swimming. Total swim time: " + swimTime + " min." );
    }
}

import java.util.Random;
import java.util.Scanner;

public class FlipAgain
{
    public static void main( String[] args )
    {
        Scanner keyboard = new Scanner(System.in);
        Random rng = new Random();

        String again = "y";

        while ( again.equals("y") )
        {
            int flip = rng.nextInt(2);
            String coin;

            if ( flip == 1 )
                coin = "HEADS";
            else
                coin = "TAILS";

            System.out.println( "You flip a coin and it is... " + coin );

            System.out.print( "Would you like to flip again (y/n)? " );
            again = keyboard.next();
        }
    }
}

import java.util.Random;

public class ShorterDoubleDice
{
    public static void main( String[] args )
    {
        Random r = new Random();

        int roll1, roll2;

        System.out.println( "HERE COMES THE DICE!" );

        do
        {
            roll1 = 1 + r.nextInt(6);
            roll2 = 1 + r.nextInt(6);

            System.out.printf( "\nRoll #1: %s" , roll1 );
            System.out.printf( "\nRoll #2: %s" , roll2 );
            System.out.printf( "\nThe total is %s!\n" , roll1 + roll2 );
        } while ( roll1 != roll2 );
    }
}

import java.util.Random;
import java.util.Scanner;

public class AgainWithTheNumberGuessing
{
    public static void main( String[] args )
    {
        Random r = new Random();
        Scanner keyboard = new Scanner(System.in);
        int number = 1 + r.nextInt(10);
        int guess;
        int tries = 0;

        System.out.println( "I have chosen a number between 1 and 10.  Try to guess it." );
        do
        {
            System.out.print( "Your guess: " );
            guess = keyboard.nextInt();

            if ( guess != number )
                System.out.println( "That is incorrect.  Guess again." );

            tries++;
        } while ( guess != number );

        System.out.println( "That's right!  You're a good guesser." );
        System.out.printf( "It only took you %s tries.\n" , tries );
    }
}

import java.util.Scanner;

public class BabyCalculator
{
    public static void main( String[] args )
    {
        Scanner keyboard = new Scanner(System.in);
        double a, b, c;
        String op;

        do
        {
            System.out.print("> ");
            a = keyboard.nextDouble();
            if ( a == 0 )
            {
                System.out.println("Bye, now.");
                break;
            }

            op = keyboard.next();
            b = keyboard.nextDouble();

            if ( op.equals("+") )
            {
                c = a + b;
            }
            else if ( op.equals("-") )
            {
                c = a - b;
            }
            else if ( op.equals("*") )
            {
                c = a * b;
            }
            else if ( op.equals("/") )
            {
                c = a / b;
            }
            else
            {
                System.out.println("Undefined operator: " + op);
                continue;
            }

            System.out.println(c);
        } while ( true );
    }
}