Java Lab

Tasks #1 & #2

Task #1 The while Loop

1) Open the file DiceSimulation.java attached below. Create a new project on NetBeans called DiceSimulation. Copy the code from the file into it. Note that DiceSimulation.java is incomplete. Since there is a large part of the program missing, the output will be incorrect if you run DiceSimulation.java.

2) I have declared all the variables. You need to add code to simulate rolling the dice and keeping track of the doubles. Convert the algorithm below into Java code and place it in the main method after the variable declarations, but before the output statements. You will be using several control structures: a while loop and an if-else-if statement nested inside another if statement. Use the indenting of the algorithm to help you decide what is included in the loop, what is included in the if statement, and what is included in the nested if-else-if statement.

Repeat while the number of dice rolls are less than the number of times the dice should be rolled.

Get the value of the first die by rolling the first die

Get the value of the second die by rolling the second die

If the value of the first die is the same as the value of the second die

If value of first die is 1

Increment the number of times snake eyes were rolled

Else if value of the first die is 2

Increment the number of times twos were rolled

Else if value of the first die is 3

Increment the number of times threes were rolled

Else if value of the first die is 4

Increment the number of times fours were rolled

Else if value of the first die is 5

Increment the number of times fives were rolled

Else if value of the first die is 6

Increment the number of times sixes were rolled

Increment the number of times the dice were rolled

Note: To roll the dice, use the nextInt method of the random number generator to generate an integer between 1 and 6.

3) Compile and run you program. You should get numbers that are somewhat close to 278 for each of the different pairs of doubles. Run it several times. You should get different results than the first time, but again it should be somewhat close to 278.

//

Task #2 Using Other Types of Loops

1) Change the while loop to a do-while loop. Compile and run. You should get the same results.

2) Change the do-while loop to a for loop. Compile and run. You should get the same results.

//

Code Listing 4.1 (DiceSimulation.java)

import java.util.Random; // Needed for the Random class

/**

This class simulates rolling a pair of dice 10,000 times and counts the number of times doubles of are rolled for each different pair of doubles.

*/

public class DiceSimulation

{

public static void main(String[] args)

{

final int NUMBER = 10000; // Number of dice rolls

// A random number generator used in

// simulating the rolling of dice Random generator = new Random();

int die1Value; // Value of the first die

int die2Value; // Value of the second die

int count = 0; // Total number of dice rolls

int snakeEyes = 0; // Number of snake eyes rolls

int twos = 0; // Number of double two rolls

int threes = 0; // Number of double three rolls

int fours = 0; // Number of double four rolls

int fives = 0; // Number of double five rolls

int sixes = 0; // Number of double six rolls

// TASK #1 Enter your code for the algorithm here

// Display the results

System.out.println ("You rolled snake eyes " + snakeEyes + " out of " + count + " rolls.");

System.out.println ("You rolled double twos " + twos + " out of " + count + " rolls.");

System.out.println ("You rolled double threes " + threes + " out of " + count + " rolls.");

System.out.println ("You rolled double fours " + fours + " out of " + count + " rolls.");

System.out.println ("You rolled double fives " + fives + " out of " + count + " rolls.");

System.out.println ("You rolled double sixes " + sixes + " out of " + count + " rolls.");

}

}