Inconsistent output after the "while loop" in JAVA - java

I am new to JAVA and wrote a Nim game project, which includes Nimsys and Nimplayer.
Everything seems fine. When I run through the test file, the result is CORRECT.
However, when it goes to playing again, there's an extra space suddenly shows up, and I cannot
figure it out. There could be some mistakes. Any help is highly appreciated.
The test results
import java.util.Scanner;
public class Nimsys {
int stoneBalance;
public static void main(String[] args) {
String playOrNot;
Scanner input = new Scanner(System.in);// Scanner
System.out.println("Welcome to Nim\n");
// bring two players in the main.
System.out.println("Please enter Player 1's name:");
NimPlayer player1 = new NimPlayer(); // bring player1 object to be used
String name1 = input.nextLine(); // set the string's name to be used
System.out.println("");
NimPlayer player2 = new NimPlayer(); // bring player2 object to be used
System.out.println("Please enter Player 2's name:");
String name2 = input.nextLine();
System.out.println("");
do {
// stone upper bound
System.out.println("Please enter upper bound of stone removal:");
int removeUpBound = input.nextInt();
System.out.println("");
// intital stone numbers
System.out.println("Please enter initial number of stones:");
int totalStone = input.nextInt();
System.out.println("");
NimPlayer numStone = new NimPlayer(); // bring new object to be used
numStone.initialStone(totalStone);
System.out.print(numStone.stoneBalance + " stones left:");
numStone.printStar(totalStone);
// while stoneBalance > 0, two players keep playing the game
while (numStone.stoneBalance > 0) {
// player1's turn and remove the stones; decision of winning
player1.enterName(name1); // pass the name to be used
player1.player1Turn();
int takeStone = input.nextInt();
while (takeStone > removeUpBound || takeStone <= 0) {
System.out.println(
"Invalid, you need to remove stones under upper bound limit or above 0. \n Please enter again.");
takeStone = input.nextInt();
}
numStone.removeStones(takeStone);
if (numStone.stoneBalance > 0) {
System.out.print(numStone.stoneBalance + " stones left:");
numStone.printStar(numStone.stoneBalance);
} else if (numStone.stoneBalance <= 0) {
System.out.println("Game Over\n" + name2 + " wins!\n");
break;
}
// player2's turn and remove the stones; decision of winning
player2.enterName(name2); // pass the name to be used
player2.player2Turn();
int takeStone2 = input.nextInt();
while (takeStone2 > removeUpBound || takeStone2 <= 0) {
System.out.println(
"Invalid, you need to remove stones under upper bound limit or above 0. \n Please enter again.");
takeStone2 = input.nextInt();
}
numStone.removeStones(takeStone2);
if (numStone.stoneBalance > 0) {
System.out.print(numStone.stoneBalance + " stones left:");
numStone.printStar(numStone.stoneBalance);
} else if (numStone.stoneBalance <= 0) {
System.out.println("Game Over\n" + name1 + " wins!\n");
break;
}
}
System.out.println("Do you want to play again (Y/N):");
playOrNot = input.next();
} while (playOrNot.equals("Y"));
}
}
public class NimPlayer {
String player1;
String player2;
int stoneBalance;
int stars;
public void enterName(String name) {
player1 = name;
player2 = name;
}
public void initialStone(int startStones) {
stoneBalance = startStones;
}
public void removeStones(int stonesTaken) {
int updatedBalance = stoneBalance - stonesTaken;
stoneBalance = updatedBalance;
}
public void player1Turn() {
System.out.println(player1 + "'s turn - remove how many?\n");
}
public void player2Turn() {
System.out.println(player2 + "'s turn - remove how many?\n");
}
public void printStar(int star) {
stars = star;
stars = stoneBalance;
for (int stars = 1; stars <= star; stars++) {
System.out.print(" *");
}
System.out.println();
}
}

To entirely fix your 2 issues I would do the following -
input.nextLine();
System.out.println("Do you want to play again (Y/N):");
playOrNot = input.nextLine();
Instead of
System.out.println("Do you want to play again (Y/N):");
playOrNot = input.next();

Related

How can I start the program over again

I'm trying to start the game over if the user enters "Yes". I tried using a while loop, but it's gone wrong somewhere that I can't find.
import java.util.Scanner;
import java.util.Random;
public class RockPaperScissors {
public static void main(String[] args) {
int playerScore = 0;
int computerScore = 0;
int round = 0;
String decision;
// Get user input
while (round<3) {
System.out.println("Please enter your move: Rock, Paper or Scissors");
System.out.println(">>");
Scanner input = new Scanner(System.in);
String playerMove = input.next();
// Check if user input is valid
if (!playerMove.equalsIgnoreCase("Rock") && !playerMove.equalsIgnoreCase("Paper") && !playerMove.equalsIgnoreCase("Scissors")) {
System.out.println("Move is invalid, Opponent gets a point");
computerScore++;
round++;
System.out.println("Your point is "+ playerScore + "; Opponent score is "+ computerScore);
} else {
// Randomly generate computerMove
int computerInt = (int)(Math.random()*3);
String computerMove = " ";
if (computerInt == 0) {
computerMove = "Rock";
} else if (computerInt == 1) {
computerMove = "Paper";
} else if (computerInt == 2) {
computerMove = "Scissors";}
System.out.println("Opponent move is "+ computerMove);
// Establish winning or losing scenarios
if (playerMove.equalsIgnoreCase(computerMove)) {
System.out.println("Tied");
round++;
System.out.println("Your point is "+ playerScore + "; Opponent score is "+ computerScore);
} else if (playerMove.equalsIgnoreCase("Rock") && computerMove.equalsIgnoreCase("Scissors") ||
playerMove.equalsIgnoreCase("Scissors") && computerMove.equalsIgnoreCase("Paper") ||
playerMove.equalsIgnoreCase("Rock") && computerMove.equalsIgnoreCase("Paper")) {
System.out.println("You won");
playerScore++;
round++;
System.out.println("Your point is "+ playerScore + "; Opponent score is "+ computerScore);
}
else {
System.out.println("You lost");
computerScore++;
round++;
System.out.println("Your point is "+ playerScore + "; Opponent score is "+ computerScore);
}
}
// Determine the last winner
if (playerScore < computerScore) {
System.out.println("You lose, so sad ;(");
} else if (playerScore > computerScore) {
System.out.println("You win, here's a cookie ;) ");
} else {
System.out.println("Tied, maybe try harder ^_^"); }
}
System.out.println("Do you wanna play again?");
}
}
}
Sounds like this might be a HW or Test question, so just writing steps to help you out:
first have a user-decision variable and initialize it to "Y"
then put the game in a while(user-decision="Y") loop
at the end of this loop ask the user for their decision and update the user-decision variable to either Y or N
if they say Y loop continues, else it ends
if you need to repeat your code, put it in a new class (Game) and instantiate in main () and call until your Game class returns TRUE (press Y)
package appMain;
import java.util.Scanner;
public class Game {
public Boolean PlayGame() {
System.out.println("START GAME");
//
// >> PUT THERE YOUT GAME CODE <<
//
Scanner input = new Scanner(System.in);
String answer = input.next();
if(answer.equals("Y")) {
return true;
}
return false;
}
}
package appMain;
public class GameMain {
public static void main(String args[]) {
Game game = new Game();
while (game.PlayGame()) {
}
System.out.println("GAME finish");
}
}

Best way to code my unintelligent Nim game?

This is my nim game (goal is dont be the last person to pick up marbles), can someone please guide me. In playing the game, I have just one question
How can I keep track of whose turn it is, I guess if I can keep track of that I can monitor my remainingMarbles. This is the crux of my code. Please help
public class Nim{
public static void main(String[] args)
{
System.out.println("************** Welcome to the game of Nim *******************");
System.out.println("The object of this game is to make me take the last marble off the table");
System.out.println("You must take at least 1 and you can take up to 3 marbles on your turn");
System.out.println("You can go first");
Scanner scan = new Scanner(System.in);
final int MARBLES = 13;
int remainingMarbles;
String input;
do {
//boolean whoseTurn = true;
remainingMarbles = MARBLES;
System.out.println("There are " + MARBLES + " marbles on the table");
while (remainingMarbles > 0){
remainingMarbles -= getUserSelection();
System.out.println("There are " + (remainingMarbles -= getComputerSelection()) + " marble(s) on the table.");
}
if (1 <= remainingMarbles && remainingMarbles <= 2 && remainingMarbles < 0) {
System.out.println("Congratulations! you won!");
System.out.println("Want to play again? y/n");
input = scan.nextLine();
input = input.toLowerCase();
} else
System.out.println("Hard luck you lose!");
System.out.println("Want to play again? y/n");
input = scan.nextLine();
input = input.toLowerCase();
}while (input.charAt(0) == 'y');
}
private static int getUserSelection()
{
Scanner scan = new Scanner(System.in);
do {
System.out.println("Enter 1, 2 or 3");
int userSelection = scan.nextInt();
if (isValidMove(userSelection)){
return userSelection;
}
else {
System.out.println("Not a valid entry");
}
}while (true);
}
private static boolean isValidMove(int input)
{
return 1 <= input && input <= 3;
}
private static int getComputerSelection ()
{
Random generator = new Random();
int computerSelection = 1 + generator.nextInt(3);
System.out.println("The computer chooses " + computerSelection);
return computerSelection;
}
}
First, make a boolean before the loop.
boolean whoseTurn = true;
When the variable is true it's the first player's turn, otherwise the second player's turn.
Now inside the while loop we change the variable at the end of every repetition:
whoseTurn = !whoseTurn;
(Which is a faster way of this)
if(whoseTurn) whoseTurn = false;
else whoseTurn = true;
To conclude, you should do something like that:
...
boolean whoseTurn = true;
while(remainingMarbles > 0){
remainingMarbles -= getUserSelection();
System.out.println("There are " + (remainingMarbles -= getComputerSelection()) + " marble(s) on the table.");
whoseTurn = !whoseTurn;
}
...

Having trouble w/ returning and passing values; "counting"

Our task was to create a guessing game, where the computer would generate a number and the user was prompted to guess. We were to create a method to play only one game, and then create a while loop in the main to make the game playable again. In the end, we need to show statistics. I'm having trouble with showing the "best game." That is a game where the amount of guesses is the least.
Here is the code:
import java.util.Random;
import java.util.Scanner;
public class GuessingGame {
public static final int MAX = 100;
// This is the main. Here we can see a do/while loop
// and a few variables that were created to compliment it.
public static void main(String[] args) {
Random rand = new Random();
Scanner console = new Scanner(System.in);
intro();
String s = "";
int totalGames = 0;
int totalGuess = 0;
do {
totalGuess = game(console);
System.out.print("Do you want to play again? ");
s = console.next();
totalGames++;
} while (s.equals("y") || s.equals("Y") || s.equals("Yes") ||
s.equals("yes") || s.equals("Yes"));
totalGuess = totalGuess;
statistics(totalGames, totalGuess);
}
// This method prints out the intro.
public static void intro() {
System.out.println("This program allows you to play a guessing
game.");
System.out.println("I will think of a number between 1 and");
System.out.println(MAX + " and will allow you to guess until");
System.out.println("you get it. For each guess, I will tell you");
System.out.println("whether the right answer is higher or lower");
System.out.println("than your guess.\n ");
}
// This method plays the game only once. It's later used in the main.
// Returns the
// number of guesses for one game.
public static int game(Scanner console) {
Random rand = new Random();
int random = rand.nextInt(MAX) + 1;
System.out.println("I'm thinking of a number between 1 and " + MAX + "
... (it's " + random + " )");
System.out.print("Your guess? > ");
int guess = console.nextInt();
int count = 0;
do {
if ((random - guess) > 0) {
System.out.println("It's higher.");
System.out.print("Your guess? > ");
guess = console.nextInt();
count++;
}
else if ((random - guess) < 0) {
System.out.println("It's lower.");
System.out.print("Your guess? > ");
guess = console.nextInt();
count++;
}
else if (random == guess) {
count++;
}
} while (random != guess);
if (count == 1) {
System.out.println("You got it right on the first guess!!");
}
else {
System.out.println("You got it right in " + count + " guesses.");
}
return count;
}
// This method prints out the statistics.
public static void statistics(int x, int y) {
System.out.println("total games = " + x);
System.out.println("total guesses = " + (y));
System.out.println("guesses/game = ");
System.out.println("best game = ");
}
}
Have a look when totalGuess is assigned:
public static void main(String[] args) {
Random rand = new Random();
Scanner console = new Scanner(System.in);
intro();
String s = "";
int totalGames = 0;
int totalGuess = 0;
// ^ Initialized to zero
do {
totalGuess = game(console);
// ^ Assigned (not added) to the return value from game.
// Did you mean: totalGuess += game(console); ?
System.out.print("Do you want to play again? ");
s = console.next();
totalGames++;
} while (s.equals("y") || s.equals("Y") || s.equals("Yes") ||
s.equals("yes") || s.equals("Yes"));
totalGuess = totalGuess;
// ^ Assigned to itself. No action.
statistics(totalGames, totalGuess);
}

Having issues with having a program re-run

I am writing a program that will ask the user to guess a random number 6 times. The program has to ask if they want to play again and will keep a running total of the wins/losses.
How would I have the program rerun?
heres the code:
import java.util.Scanner;
import java.util.Random;
public class Project {
public static void main(String[] args) {
String input;
double guess = 0;
int number;
double wins = 0;
double losses = 0;
String repeat;
Scanner keyboard = new Scanner(System.in);
Random randomNumbers = new Random();
System.out.println("Welcome to Higher/Lower!");
System.out.println("Enter your name: ");
input = keyboard.nextLine();
while(input.equalsIgnoreCase("yes")); {
number = randomNumbers.nextInt(100) + 1;
System.out.println("I've chosen my number, " + input + "You only have 6 tries, good luck!"); }
for(int num = 1; number != guess && number <= 6; num++) {
System.out.println("Enter guess " + num + ":");
guess = keyboard.nextDouble();
if(guess < number)
System.out.println("higher.");
else if(guess > number)
System.out.println("lower.");
else
System.out.println("Congratulations!"); }
if(guess == number) {
System.out.println("You guesses my number!"); wins++; }
if(guess != number) {
System.out.println("Sorry, " + input + " my number was " + number +
"You lose!"); losses++; }
System.out.println("Do you want to play again? (Yes/No): ");
repeat = keyboard.nextLine();
if(input.equalsIgnoreCase("no")); {
System.out.println("Thanks for playing!"); }
System.out.println(wins + " wins");
System.out.println(losses + " losses");
}
}
It is skipping over asking me if i want to play again or not and i dont know what kind of loop to use
Wihtout your code, I'm assuming this is what you need.
boolean doContinue = true;
do {
//guess random number 6 times
//do you want to continue?
// yes -> doContinue = true;
// no -> doContinue = false;
} while (doContinue );
I would suggest making your loop a do-while loop like this:
do {
for (int i=0; i<6; i++){
/*
insert code for the guessing/checking/etc.
*/
}
System.out.print("Would you like to continue? [Y/n] ");
} while (scan.next().toUpperCase().charAt(0) != 'Y');

Rock paper scissors, play again?

For my assignment I'm supposed make the program rock paper scissors which I figured that out my main problem is I can't get the program to play again right or get the program to calculate the game scores correctly pleas help I'm going crazy trying to figure this out?!
//Tayler Dorsey
import java.util.Random;
import java.util.Scanner;
public class PRS {
static Scanner keyboard = new Scanner(System. in );
public static void instructions() {
System.out.println("This is the popular game of paper, rock, scissors. Enter your\nchoice by typing the word \"paper\", the word \"rock\" or the word\n\"scissors\". The computer will also make a choice from the three\noptions. After you have entered your choice, the winner of the\ngame will be determined according to the following rules:");
System.out.println("Paper wraps rock (paper wins)\nRock breaks scissors (rock wins)\nScissors cuts paper (scissors wins)");
System.out.println("If both you and the computer enter the same choice, then the game is tied.");
}
public static int playGame() {
int ties = 0, wins = 0, losts = 0;
String userchoice, computerchoice;
System.out.println("Enter your choice: ");
userchoice = keyboard.next();
computerchoice = computerChoose();
System.out.println("You entered: " + userchoice);
System.out.println("Computer choose: " + computerchoice);
if ((userchoice.equals("paper") && computerchoice.equals("paper")) || (userchoice.equals("rock") && computerchoice.equals("rock")) || (userchoice.equals("scissors") && computerchoice.equals("scissors"))) {
System.out.println("IT'S A TIE!");
ties++;
return 3;
} else if ((userchoice.equals("paper") && computerchoice.equals("rock")) || (userchoice.equals("rock") && computerchoice.equals("scissors")) || (userchoice.equals("scissors") && computerchoice.equals("paper"))) {
System.out.println("YOU WIN!");
wins++;
return 1;
} else {
System.out.println("YOU LOSE!");
losts++;
return 2;
}
}
public static String computerChoose() {
Random generator = new Random();
String[] answer = new String[3];
answer[0] = "paper";
answer[1] = "rock";
answer[2] = "scissors";
return answer[generator.nextInt(3)];
}
public static void main(String[] args) {
String play;
Scanner keyboard = new Scanner(System. in );
System.out.println("The Game of Paper, Rock, Scissors");
System.out.println("Do you need instructions (y or n)?");
String help = keyboard.nextLine();
if (help.equals("y")) instructions();
int result = playGame();
System.out.println("Play again (y or n)?");
play = keyboard.nextLine();
if (play.equals("y"));
else {
int count = 0, wins = 0, losts = 0, ties = 0;
System.out.println("Games played: " + count);
System.out.println("Wins for you: " + wins);
System.out.println("Wins for me: " + losts);
System.out.println("Tied games: " + ties);
}
do {} while (play == "y"); {
playGame();
int count = 0;
count++;
}
}
}
There are two issues here:
The code isn't inside the do-while loop, it's after it.
String equality should be checked with equals not with ==.
So:
int count = 0;
do { // Note the code inside the do-while block
playGame();
count++;
} while (play.equals("y")); // Note the use of equals
Do the following:
do {
play = keyboard.nextLine();
if (play.equals("y")){
}
else {
int count = 0, wins = 0, losts = 0, ties = 0;
System.out.println("Games played: " + count);
System.out.println("Wins for you: " + wins);
System.out.println("Wins for me: " + losts);
System.out.println("Tied games: " + ties);
}
} while (play.equals("y"));
In order to calculate the games scores make those variable global.
public class PRS {
static Scanner keyboard = new Scanner(System. in );
int ties = 0, wins = 0, losts = 0;

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