I am having a problem with my java battleship program not printing the coordinates that the user enters. When the user guesses a spot on the board its supposed to update the space with an "X" if its a hit, if not then the board remains the same. But when a user guesses wrong on my program, it prints everything except the space where the user guessed. I believe that my else statement where the board updates is the problem, but any modification I did resulted in the board not printing anything.
import java.util.Random;
import java.util.Scanner;
class Battleship {
public static char randChar(){
final String alphabet = "ABCDE";
final int N = alphabet.length();
char rand;
Random r = new Random();
rand = alphabet.charAt(r.nextInt(N));
return rand;
}
public static void main (String[] args) throws java.lang.Exception {
char[] letters = {' ', 'A', 'B', 'C', 'D', 'E'};
int[] numbers ={1, 2, 3, 4, 5};
int[][] ships = new int[7][2];
char colGuess;
int rowGuess;
Boolean boardFlag=false;
Scanner scan = new Scanner(System.in);
//creates the board
for (int i = 0 ; i <= 5 ; i++) {
for (int j = 0 ; j <= 5 ; j++) {
if (i == 0) {
System.out.print(letters[j] + " ");
}
else if (j == 0) {
System.out.print(numbers[i - 1]);
}
else {
System.out.print(letters[j] + "" + numbers[i-1]);
}
System.out.print(" ");
}
System.out.println();
}
//assigns ships to random spots
assignShips(ships);
System.out.println("Enter your guess for the column:");
colGuess = scan.next().charAt(0);
//converts to uppercase
colGuess = Character.toUpperCase(colGuess);
System.out.println("Enter your guess for the row:");
rowGuess = scan.nextInt();
//shows player what they entered
System.out.println("you entered: " + (char) colGuess + rowGuess);
//calls method to check for a hit
fire(colGuess, rowGuess, ships);
boardFlag = fire(colGuess, rowGuess, ships);
System.out.println(boardFlag);
//updates the board
for (int i = 0 ; i <= 5 ; i++) {
for (int j = 0 ; j <= 5 ; j++) {
if (i == 0) {
System.out.print(letters[j] + " ");
}
else if (j == 0) {
System.out.print(numbers[i - 1]);
}
else {
if(letters[j] == colGuess && numbers[i - 1] == rowGuess) {
if(boardFlag==true) {
System.out.print(" " + "X");
}
}
else {
System.out.print(letters[j] + "" + numbers[i - 1]);
}
}
System.out.print(" ");
}
System.out.println();
}
}
public static void assignShips(int[][] ships) {
Random random = new Random();
for(int ship = 0; ship < 7; ship++) {
ships[ship][0] = randChar();
ships[ship][1] = random.nextInt(5);
//gives location of ships, for testing purposes
System.out.print("Ship:" + (ship+1)+ " is located at"+(char)ships[ship][0]+ships[ship][1]+"\n");
}
}
//checks user input to see if we have a hit
public static Boolean fire(char colGuess, int rowGuess, int[][] ships) {
Boolean hitFlag=false;
for(int ship = 0; ship < ships.length; ship++){
if(colGuess ==ships[ship][0] && rowGuess == ships[ship][1]){
hitFlag=true;
}
}
if(hitFlag == true) {
System.out.println("we hit em at "+(char)colGuess+rowGuess+" chief!");
}
else {
System.out.println("sorry chief we missed em");
}
return hitFlag;
}
}
The reason its not showing up when you miss is because your net telling it to print anything.
if(letters[j] == colGuess && numbers[i-1] == rowGuess){
if(boardFlag==true) {
System.out.print(" "+"X");
}
}
Your only handling the coordinate the user input if they hit. To fix this you would need an else statement after your if(boardFlag == true)to handle printing if you miss.
The problem is in your update board portion of the code because you don't do anything if the guessed location isn't a hit.
if(letters[j]==colGuess && numbers[i-1]==rowGuess && boardFlag) {
System.out.print(" "+"X");
} else {
System.out.print(letters[j]+""+numbers[i-1]);
}
Full Update Portion:
//updates the board
for (int i = 0 ; i <= 5 ; i++){
for (int j = 0 ; j <= 5 ; j++){
if (i == 0) {
System.out.print(letters[j]+" ");
} else if (j == 0){
System.out.print(numbers[i-1] );
} else {
if(letters[j]==colGuess && numbers[i-1]==rowGuess && boardFlag){
System.out.print(" "+"X");
} else {
System.out.print(letters[j]+""+numbers[i-1]);
}
}
System.out.print(" ");
}
System.out.println();
}
This block (old version):
if(hitFlag==true){
System.out.println("we hit em at "+(char)colGuess+rowGuess+" chief!");
} else {
System.out.println("sorry chief we missed em");
}
Should be (new version):
if(hitFlag==true){
System.out.println("we hit em at "+(char)colGuess+rowGuess+" chief!");
} else {
System.out.println("sorry chief we missed em at " + (char)colGuess+rowGuess);
}
this will print:
sorry chief we missed em at D3 //D3 is a random possible set of coordinates
Rather than:
sorry chief we missed em //Old version
So all you have to add is (char)colGuess+rowGuess, which prints the coordinates of your previous guess.
Comment if you have any questions!
Related
package Demo;
import java.util.Scanner;
public class seat_reservation{
public static void main(String[] args) {
Scanner read = new Scanner(System.in);
// Initialization
final int ROWS = 2;
final int COLS = 3;
char [][] seats = new char [ROWS][COLS];
int i, j, seatNum, counter = 0;
char seatLetter = 'A';
int choice = 0;
String seatEnter;
boolean cont = true; // loops of running the program
while( choice != 4 ){
System.out.print( "1. Assign Seats" );
System.out.print( "2. Exit" );
System.out.print( "Select your choice: " );
choice = read.nextInt();
switch( choice ){
case 1:
//Set the value.
for (i=0; i < seats.length; i++) {
for (j=0; j < seats[i].length; j++)
seats[i][j] = seatLetter++;
seatLetter = 'A'; // to reset the value to A for the new loop
}
//To display the list of seats
for (i=0; i < seats.length; i++) {
System.out.print((i+1)+" ");
for (j=0; j < seats[i].length; j++)
System.out.print(seats[i][j]+" ");
System.out.println();
}
//condition
while (counter < 6 && cont) {
do {
System.out.print("Please type the chosen seat(starts with row and column,e.g:2A):" + "");
seatEnter = (read.nextLine()).toUpperCase(); //covert to Upper case
seatNum = Integer.parseInt(seatEnter.charAt(0)+"");
if (seatNum != 0)
seatLetter = seatEnter.charAt(1);
i++;
//if user enters wrong input, error message will appear.
if (seatLetter!='A'){
if (seatLetter!='B'){
if(seatLetter!='C'){
if(seatLetter!='D')
System.out.println ("Invalid! Please enter the correct seat:");
}
}
}
}
//continue to loop until the condition true
while (seatNum < 0 || seatNum > 7 || seatLetter < 'A' || seatLetter > 'D');
if (seatNum == 0) {
cont = false;
} else {
if (seats[seatNum-1][seatLetter-65] == 'X')
System.out.println("Seat have been taken.Please choose another seat:");
else {
seats[seatNum -1][seatLetter-65] = 'X';
counter++;
}
// To display updated lists of seats
for (i=0; i < seats.length; i++) {
System.out.print((i+1)+" ");
for (j=0; j < seats[i].length; j++)
System.out.print(seats[i][j] + " ");
System.out.println();
}
System.out.println(" ") ;
//}
//}
// displays fully booked message
if (counter == 6)
System.out.println("All seats are now fully-booked.");
break;
}
}
case 2://syntax error here
if (counter == 6)
System.out.println( "All seats are now fully-booked." );
System.out.println( "End of Program" );
System.exit(0);
break;
default:
System.out.println("Error input");
break;//syntax error here as well.
}
}
}
}
The problem is caused due to:
choice = read.nextInt();
The scanner.nextInt() only takes the next token from the input. Rest are ignored by it.
So when you're trying to take the next input from this line and process it, the error occurs:
seatEnter = (read.nextLine()).toUpperCase(); //covert to Upper case
seatNum = Integer.parseInt(seatEnter.charAt(0) + "");
As the previous read.nextInt() left the rest except first token, when you hit enter after giving 1 as input, it took only the 1 and the enter or newline token was captured by the read.nextLine(). That is why it got no charAt(0) and thus thrown StringIndexOutOfBoundException.
Try:
choice = Integer.parseInt(read.nextLine());
or,
choice = read.nextInt();
read.nextLine(); // this will capture the residue
I am writing a penny pitch program in java and it is a carnival game. Prizes are randomly generated on a board and 10 coins are thrown. In the "randSelector" method I have written, I am getting an error from "prize" because it says I cant return a String to String []. Any Suggestions? This is my code:
import java.util.Arrays;
import java.util.Random;
public class PennyPitch {
public static void main(String[] args) {
// TODO Auto-generated method stub
Random rand = new Random();
String[][] board = new String[25][25];
int puzzle = 0;
int poster = 0;
int doll = 0;
int ball = 0;
int game = 0;
int misses = 0;
//Create empty board
Arrays.fill(board, "[ ]");
String[] prizes = {"[ puzzle ]", "[ poster ]", "[ doll ]", "[ ball ]", "[ game ]"};
for (int i = 0; i < prizes.length; i++) {
randSelecter(board, prizes[i], rand);
}
//Simulates 10 pennies thrown
for ( int i = 0; i < 10; i++) {
for ( int j = 0; j < 10; j++){
int box = rand.nextInt(24);
if (board[box][j] == "[ puzzle ]"){
puzzle += 1;
} else if (board[box][j] == "[ poster ]"){
poster += 1;
} else if (board[box][j] == "[ doll ]"){
doll += 1;
} else if (board[box][j] == "[ ball ]"){
ball += 1;
} else if (board[box][j] == "[ game ]"){
game += 1;
}else {
misses += 1;
}
}
System.out.println("Welcome to Penny Pitch!");
System.out.println("Land on three of a kind and win the prize!");
System.out.println("You've thrown 10 pennies on the board below,\n");
//Prints 5 x 5 board
System.out.println(board[0][0] + board[1][1] + board[2][2] + board[3][3] + board[4][4]);
System.out.println(board[5][5] + board[6][6] + board[7][7] + board[8][8] + board[9][9]);
System.out.println(board[10][10] + board[11][11] + board[12][12] + board[13][13] + board[14][14]);
System.out.println(board[15][15] + board[16][16] + board[17][17] + board[18][18] + board[19][19]);
System.out.println(board[20][20] + board[21][21] + board[22][22] + board[23][23] + board[24][24] + "\n");
System.out.println("Here is your outcome:" );
System.out.println("Puzzle: " + puzzle );
System.out.println("Poster: " + poster );
System.out.println("Doll: " + doll );
System.out.println("Ball: " + ball );
System.out.println("Game: " + game );
System.out.println("Misses: " + misses );
//Checks for a win
if ( puzzle == 3){
System.out.println("You won a puzzle!");
} else if ( poster == 3) {
System.out.println("You won a poster!");
} else if ( doll == 3) {
System.out.println("You won a doll!");
} else if ( ball == 3) {
System.out.println("You won a ball!");
} else if ( game == 3) {
System.out.println("You won a game!");
} else {
System.out.println("Sorry, you lost.");
}
}
}
//Randomly place prizes
public static String[] randSelecter(String[][] board, String prize, Random rand) {
for (int i = 0; i < 3; i++) {
int pick = rand.nextInt(24);
int anotherNum = rand.nextInt(24);
if (board[pick][anotherNum] != "[ ]" && board[pick + 1][anotherNum+1] == "[ ]" && pick != 24) {
board[pick + 1] = prize;
} else if (board[pick][anotherNum] != "[ ]" && pick != 0 && board[pick - 1][anotherNum-1] == "[ ]") {
board[pick - 1] = prize;
} else if (board[pick][pick] != "[ ]") {
for (int k = 0; k < board.length; ) {
if (board[k][anotherNum] == "[ ]") {
board[k][anotherNum] = prize;
break;
} else {
k++;
}
}
} else {
board[pick] = prize;
}
}
for(int x = 0;x<30;x++) {
for(int p = 0;p<30;p++) {
return board[x][p];
}
}
}
}
Your return type in randSelecter is String[] but you're returning a String by doing return board[x][p]. Change your return type to String:
public static String randSelecter(String[][] board, String prize, Random rand) {
...
or alternatively change what you're returning
I am making a movie guessing game(much like hangman but doesn't contain the stick figure and stuff) on Java that takes input from the user, letter by letter. I am stuck where I want the letter entered to replace all instances of that letter in the title of the movie. My code is not working completely.
Later, I am gonna apply the logic that stops the user from entering the same letter again. But at the moment I need to fix this particular issue. Any help?
This is the game process function in my game class.
public void GameProcess(char[] dashedarray) {
Scanner input = new Scanner(System.in);
char guess;
int i = 0;
int spaces = 0;
int correct = 0;
int wrong = 0;
boolean run = true;
while (run) {
if (dashedarray[i] == ' ') {
spaces++;
i++;
continue;
} else {
System.out.println("Enter your guess.");
guess = input.next().charAt(0);
for (int j = 0; j < dashedarray.length; j++) {
if (dashedarray[j] != ' ') {
if (moviename.charAt(i) == guess) {
dashedarray[i] = guess;
correct++;
}
else if(moviename.charAt(j) == guess) {
dashedarray[j] = guess;
correct++;
}
}
else
{
wrong++;
}
}
i++;
PrintArray(dashedarray);
if (correct == (moviename.length() - spaces)) {
System.out.println("You have won.");
break;
} else if (wrong == 10) {
System.out.println("You have lost.");
break;
}
System.out.println("The number of wrong guesses is " + wrong + ".");
}
}
You don't need i at all. spaces is to count the number of spaces in your answer, which does not need to be guessed. You should do that outside of the loop.
Scanner input = new Scanner(System.in);
char guess;
int i = 0;
int spaces = 0;
int correct = 0;
int wrong = 0;
boolean run = true;
for (int i = 0; i < dashedarray.length; i++) {
spaces++;
}
while (run) {
System.out.println("Enter your guess.");
guess = input.next().charAt(0);
boolean match = false;
for (int j = 0; j < dashedarray.length; j++) {
if (dashedarray[j] != ' ') {
if(moviename.charAt(j) == guess) {
dashedarray[j] = guess;
correct++;
match = true;
}
}
}
// It matched nothing, this input is wrong.
if (!match) {
wrong++;
}
PrintArray(dashedarray);
if (correct == (moviename.length() - spaces)) {
System.out.println("You have won.");
break;
} else if (wrong == 10) {
System.out.println("You have lost.");
break;
}
System.out.println("The number of wrong guesses is " + wrong + ".");
}
import java.util.*;
public class HangManP5
{
public static void main(String[] args)
{
int attempts = 10;
int wordLength;
boolean solved;
Scanner k = new Scanner(System.in);
System.out.println("Hey, what's your name?");
String name = k.nextLine();
System.out.println(name+ ", hey! This is a hangman game!\n");
RandomWord(word);
int len = word.length();
char[] temp = new char[len];
for(int i = 0; i < temp.length; i++)
{
temp[i] = '*';
}
System.out.print("\n");
System.out.print("Word to date: ");
while (attempts <= 10 && attempts > 0)
{
System.out.println("\nAttempts left: " + attempts);
System.out.print("Enter letter: ");
String test = k.next();
if(test.length() != 1)
{
System.out.println("Please enter 1 character");
continue;
}
char testChar = test.charAt(0);
int foundPos = -2;
int foundCount = 0;
while((foundPos = word.indexOf(testChar, foundPos + 1)) != -1)
{
temp[foundPos] = testChar;
foundCount++;
len--;
}
if(foundCount == 0)
{
System.out.println("Sorry, didn't find any matches for " + test);
}
else
{
System.out.println("Found " + foundCount + " matches for " + test);
}
for(int i = 0; i < temp.length; i++)
{
System.out.print(temp[i]);
}
System.out.println();
if(len == 0)
{
break; //Solved!
}
attempts--;
}
if(len == 0)
{
System.out.println("\n---------------------------");
System.out.println("Solved!");
}
else
{
System.out.println("\n---------------------------");
System.out.println("Sorry you didn't find the mystery word!");
System.out.println("It was \"" + word + "\"");
}
}
public static String RandomWord(String word)
{
//List of words
Random r = new Random();
int a = 1 + r.nextInt(5);
if(a == 1)
{
word=("Peace");
}
if(a == 2)
{
word=("Nuts");
}
if(a == 3)
{
word=("Cool");
}
if(a == 4)
{
word=("Fizz");
}
if(a == 5)
{
word=("Awesome");
}
return (word);
}
}
Ok, so this is my code for a hangman game, the only thing I have left to do is to get my program to randomize one of the words, which it should do in the method successfully. But the only problem I'm having is getting the String variable "word" to go back to the main class (there are errors underlining all the "word" variables in the main class).
If I could get help with either this or another way to produce a random word from a list, that would be amazing.
In java, parameters are passed by value and not by reference. Therefore, you cannot change the reference of a parameter.
In your case, you need to do:
public static String getRandomWord() {
switch(new Random().nextInt(5)) {
case 0:
return "Peace";
case 1:
return "Nuts";
// ...
default:
throw new IllegalStateException("Something went wrong!");
}
}
And in main:
// ...
String word = getRandomWord();
int len = word.length();
// ...
You can't modify the caller's reference.
RandomWord(word);
needs to be something like
word = RandomWord(word);
Also, by convention, Java methods start with a lower case letter. And, you could return the word without passing one in as an argument and I suggest you save your Random reference and use an array like
private static Random rand = new Random();
public static String randomWord() {
String[] words = { "Peace", "Nuts", "Cool", "Fizz", "Awesome" };
return words[rand.nextInt(words.length)];
}
And then call it like
word = randomWord();
I'm doing lottery game for my assignment (user inputs 6 number, i will generate 8 unique winning numbers and 2 last numbers are supplementary). I need help with user input checking if input numbers are from 1 to 45 and input must be int, when input is not integer it throws an error.
This programming way is procedure way, how can i change it into object oriented way? I know that I must make methods in another java file and then link it back to this main. Can you suggest me how to do it?
I have tried try and catch, if and else (for input check) but i don't know how to check user input when it's in array. Thank you for help.
Here is my code:
class Lottery {
public static void main ( String[] args ) {
System.out.println("\nWelcome to the Lottery game.");
System.out.println("You can enter numbers from 1 to 45.");
// User input into an array
int[] input = new int[6];
Scanner scanner = new Scanner(System.in);
System.out.println("\nPlease enter your 6 lucky numbers: ");
for(int j = 0; j < 6; j++) {
input[j]=scanner.nextInt();
}
int check = scanner.nextInt();
if(check < 0 && check > 45) {
System.out.println("\nERROR: Please enter only numbers from 1 to 45!");
}
// Printing out unique winning numbers from random generator
System.out.println("\nWinning numbers: ");
MultiRandomGenerator mrg = new MultiRandomGenerator();
int[] set;
set = mrg.getSet();
for (int i = 0; i < set.length; i++) {
System.out.print(set[i] + " ");
}
// Loops for counting how many numbers user has guessed right
int count = 0; // for 6 numbers
int scount = 0; // for 2 last supplementary numbers
for(int i = 0; i < input.length; i++) {
for(int k = 0; k < set.length; k++) {
if (k < 6) {
if (set[k] == input[i]) {
count++;
} else {
if (set[k] == input[i]) {
scount++;
}
}
}
}
}
System.out.print("\n\nYou guessed right " + count + " winning numbers.");
System.out.print("\nYou guessed right " + scount + " suplementary numbers.");
// If statments for printing out winning prizes
if (count == 6) {
System.out.println("\nYou have won 1st price!");
} if (count == 5 && scount == 1) {
System.out.println("\nYou have won 2st price!");
} if (count == 5) {
System.out.println("\nYou have won 3st price!");
} if (count == 4) {
System.out.println("\nYou have won 4st price!");
} if (count == 3 && scount == 1) {
System.out.println("\nYou have won 5st price!");
} if (count == 1 && scount == 2) {
System.out.println("\nYou have won 6st price!");
} else {
System.out.println("\nSorry, you didn't won anything.");
}
}
}
Sample code to go through array and find the invalid user input.
set = mrg.getSet();
String[] userDataStatus = new String[45];
for (int i = 0; i < set.length; i++)
{
try
{
String inputdata = set.get(i);
if(inputdata != null && inputdata.trim().length() > 0)
{
int currentNumber = Integer.parseInt(userdata);
userDataStatus[i] = "Y";//Y represent valid number
}
}
catch (NumberFormatException ex )
{
userDataStatus[i] = "N";//If it throws exception then save as 'N'
}
}
Use the above String array and display error messaage to users.
You can check in your loop, something like
int val;
try
{
input[j] = Integer.parseInt( scanner.nextString() );
}
catch (NumberFormatException ex )
{
}