Hello everyone,

I am having a slight problem in my function "startGame". My code works on Bloodshed and the code does compile. I am trying to refine the part on making sure that only a number gets input and not a letter or any other key gets input. I have try a couple different ways and it is not coming out the way I think it should. I have tried a do/while loop and a if/else statement. Does anyone have a sugestion.

#include <iostream>
#include <cstdlib>
using namespace std;
class ticTac
{
      private:
             int counter;
             char posn[9];
             char player;
      public:
             void nextPlayer();
             char getPlayer();
             void newBoard();
             void startGame();
             char checkWinner();
             bool checkPosn(int spot, char player);
             void updateBoard();
                                     
};
 
int main()
{
    char ch;
    ticTac Toe;
    do{
           Toe.newBoard();         //Brings up the new board
           Toe.startGame();        //Starts the new game
           cout << "Would you like to play again (Enter 'y')? ";
           cin >> ch;
           }while (ch == 'y');
 
    return 0;    
}

//The new board before the game starts
void ticTac::newBoard()
{
 
     char posndef[9] = {'0', '1', '2', '3', '4', '5', '6', '7', '8'};
     int i;
     counter = 0;
     player = 'x';
     for (i=0; i<9; i++) posn[i]=posndef[i];
     return;
 
}

//This will update the board with the 'X' or 'O'
void ticTac::updateBoard()
{
     cout << "\n\n" <<endl;
     cout << "\n\n\t\t" <<posn [0]<< "   | " <<posn [1]<< "  | " <<posn [2]<<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << " \t\t ___|____|___ " <<endl;
     cout << "\n\n\t\t" <<posn [3]<< "   | " <<posn [4]<< "  | " <<posn [5]<<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << " \t\t ___|____|___ " <<endl;
     cout << "\n\n\t\t" <<posn [6]<< "   | " <<posn [7]<< "  | " <<posn [8]<<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << "\n" <<endl;
      
}

//Starts the game
void ticTac::startGame()
{
     int spot;
     char blank = ' ';
     bool result = false;
     char posndef[9] = {'0', '1', '2', '3', '4', '5', '6', '7', '8'};
      
     cout << "\n\nPlayer " << getPlayer() <<" will be the first to play." <<endl;
 
     do {
         updateBoard();              // display update board   
 
         cout << "Player " << getPlayer() <<" choose a position between (0 - 8)." <<endl;
         cin >> spot;
          
         if (spot < 0 || spot > 8)
         {
              cout << "Invalid position! Please input a number of 0 thru 8." <<endl;
              continue;}
              
          
                                
         result = checkPosn(spot, getPlayer());            // to check if the position is taken
                      
         system("CLS"); 
         
         if (result == false){
             nextPlayer(); }
          
         if(checkWinner() == 'x' || checkWinner() == 'o' || checkWinner () == 't')
             blank = 'v';
         }
         while ( blank != 'v' );

 
         return;
 
}

//Checks to see who the winner will be     
char ticTac::checkWinner()
{
     char game = ' ';
     int check = 1;
 
     // Check if X wins   
     if (posn[0] == 'x' && posn[1] == 'x' && posn[2] == 'x') game = 'x';
     if (posn[3] == 'x' && posn[4] == 'x' && posn[5] == 'x') game = 'x';
     if (posn[6] == 'x' && posn[7] == 'x' && posn[8] == 'x') game = 'x';
     if (posn[0] == 'x' && posn[3] == 'x' && posn[6] == 'x') game = 'x';
     if (posn[1] == 'x' && posn[4] == 'x' && posn[7] == 'x') game = 'x';
     if (posn[2] == 'x' && posn[5] == 'x' && posn[8] == 'x') game = 'x';
     if (posn[0] == 'x' && posn[4] == 'x' && posn[8] == 'x') game = 'x';
     if (posn[2] == 'x' && posn[4] == 'x' && posn[6] == 'x') game = 'x';
     if (game == 'x' )  
       {cout << "Player1 wins the game." <<endl; return game; };
 
     // Check if O wins     
     if (posn[0] == 'o' && posn[1] == 'o' && posn[2] == 'o') game = 'o';
     if (posn[3] == 'o' && posn[4] == 'o' && posn[5] == 'o') game = 'o';
     if (posn[6] == 'o' && posn[7] == 'o' && posn[8] == 'o') game = 'o';
     if (posn[0] == 'o' && posn[3] == 'o' && posn[6] == 'o') game = 'o';
     if (posn[1] == 'o' && posn[4] == 'o' && posn[7] == 'o') game = 'o';
     if (posn[2] == 'o' && posn[5] == 'o' && posn[8] == 'o') game = 'o';
     if (posn[0] == 'o' && posn[4] == 'o' && posn[8] == 'o') game = 'o';
     if (posn[2] == 'o' && posn[4] == 'o' && posn[6] == 'o') game = 'o';
     if (game == 'o' )
       {cout << "Player2 wins the game." <<endl; return game; };
     
     for(int i = 0; i < 8; i++ ){
         if(posn[i] >= '1' && posn[i] <= '8' ){
             check = 0;
             break;
            } 
      } 
              
     // Check if tie
     if (game != 'x' && game != 'o' && check == 1) game = 't';
     if (game == 't')
        {cout << "Tie Game." <<endl; return game; };
      

          
     
     
     
     return game;        
}

//Checks to see if the position is taken     
bool ticTac::checkPosn(int spot, char player)
{
 
     if (posn[spot] == 'x' || posn[spot] == 'o'){
          cout << "Position already taken, please choose another position." <<endl;
          system ("pause");
          return true;
          }
          else {
                    posn[spot] = player;
                    cout << "Nice move." <<endl;
                    system ("pause");
                    counter++;
                    return false;
                   
          }
 
     
 
     return false;
 
}

//Tells the next player that it's thier turn
void ticTac::nextPlayer()
{
     if (player == 'x')
         player = 'o';
     else player = 'x';
     return;
}

//This switches between players         
char ticTac::getPlayer()
{
     return player;
}

Focus your code posting to just the pertinent part. sometimes it's hard to know where that is, but in your case it shouldn't be.

Sounds like a do/while loop using something like isdigit() might work if the numerical input is from 0-9.

Otherwise you could check the state of the stream after attempted input. If it is still a valid stream then the input was valid. If not, it wasn't and you will need to ignore the invalid input part and reset the stream.

As a further alternative you could accept input only as a string and then scan the string char by char for validity.

I am almost finished with this code. I am able to compile and when I input a number like 7 the 'x'' is placed in the zero position. What did I miss.

#include <iostream>
#include <cstdlib>
#include <cctype>

using namespace std;
class ticTac
{
      private:
             int counter;
             char posn[9];
             char player;
      public:
             void nextPlayer();
             char getPlayer();
             void newBoard();
             void startGame();
             char checkWinner();
             bool checkPosn(int spot, char player);
             void updateBoard();
                                     
};// end class ticTac
 
int main()
{
    char ch;
    ticTac Toe;
    do{
           Toe.newBoard();         //Brings up the new board
           Toe.startGame();        //Starts the new game
           cout << "Would you like to play again (Enter 'y')? ";
           cin >> ch;              // places the user input into response variable
           }while (ch == 'y');
 
    return 0;    
}// end main

//The new board before the game starts
void ticTac::newBoard()
{
 
     char posndef[9] = {'0', '1', '2', '3', '4', '5', '6', '7', '8'};
     int i;
     counter = 0;
     player = 'x';
     for (i=0; i<9; i++) posn[i]=posndef[i];
     return;
 
}// end function newBoard

//This will update the board with the 'X' or 'O'
void ticTac::updateBoard()
{
     cout << "\n\n" <<endl;
     cout << "\n\n\t\t" <<posn [0]<< "   | " <<posn [1]<< "  | " <<posn [2]<<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << " \t\t ___|____|___ " <<endl;
     cout << "\n\n\t\t" <<posn [3]<< "   | " <<posn [4]<< "  | " <<posn [5]<<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << " \t\t ___|____|___ " <<endl;
     cout << "\n\n\t\t" <<posn [6]<< "   | " <<posn [7]<< "  | " <<posn [8]<<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << " \t\t    |    |   " <<endl;
     cout << "\n" <<endl;
      
}// end funtion updateBoard

//Starts the game
void ticTac::startGame()
{
     char input;
     int spot;
     char blank = ' ';
     bool result = false;
     char posndef[9] = {'0', '1', '2', '3', '4', '5', '6', '7', '8'};
      
     cout << "\n\nPlayer " << getPlayer() <<" will be the first to play." <<endl;
 
     do {
         updateBoard();              // display update board   
 
         cout << "Player " << getPlayer() <<" choose a position between (0 - 8)." <<endl;
         cin >> input;                // places the user input into response variable
          
         if (isdigit(input))cout << " " << endl;
             else {cout << "Invalid input, Please try again" << endl;
             continue;
                          }
         int spot = atoi ( input + " " );              
         result = checkPosn(spot, getPlayer());            // to check if the position is taken
                      
         system("CLS"); 
         
         if (result == false){
             nextPlayer(); }
          
         if(checkWinner() == 'x' || checkWinner() == 'o' || checkWinner () == 't')
             blank = 'v';
         }
         while ( blank != 'v' );

 
         return;
 
}// end funtion startGame

//Checks to see who the winner will be     
char ticTac::checkWinner()
{
     char game = ' ';
     int check = 1;
 
     // Check if X wins   
     if (posn[0] == 'x' && posn[1] == 'x' && posn[2] == 'x') game = 'x';
     if (posn[3] == 'x' && posn[4] == 'x' && posn[5] == 'x') game = 'x';
     if (posn[6] == 'x' && posn[7] == 'x' && posn[8] == 'x') game = 'x';
     if (posn[0] == 'x' && posn[3] == 'x' && posn[6] == 'x') game = 'x';
     if (posn[1] == 'x' && posn[4] == 'x' && posn[7] == 'x') game = 'x';
     if (posn[2] == 'x' && posn[5] == 'x' && posn[8] == 'x') game = 'x';
     if (posn[0] == 'x' && posn[4] == 'x' && posn[8] == 'x') game = 'x';
     if (posn[2] == 'x' && posn[4] == 'x' && posn[6] == 'x') game = 'x';
     if (game == 'x' )  
       {cout << "Player1 wins the game." <<endl; return game; };
 
     // Check if O wins     
     if (posn[0] == 'o' && posn[1] == 'o' && posn[2] == 'o') game = 'o';
     if (posn[3] == 'o' && posn[4] == 'o' && posn[5] == 'o') game = 'o';
     if (posn[6] == 'o' && posn[7] == 'o' && posn[8] == 'o') game = 'o';
     if (posn[0] == 'o' && posn[3] == 'o' && posn[6] == 'o') game = 'o';
     if (posn[1] == 'o' && posn[4] == 'o' && posn[7] == 'o') game = 'o';
     if (posn[2] == 'o' && posn[5] == 'o' && posn[8] == 'o') game = 'o';
     if (posn[0] == 'o' && posn[4] == 'o' && posn[8] == 'o') game = 'o';
     if (posn[2] == 'o' && posn[4] == 'o' && posn[6] == 'o') game = 'o';
     if (game == 'o' )
       {cout << "Player2 wins the game." <<endl; return game; };
     
     for(int i = 0; i < 8; i++ ){
         if(posn[i] >= '1' && posn[i] <= '8' ){
             check = 0;
             break;
            } 
      } 
              
     // Check if tie
     if (game != 'x' && game != 'o' && check == 1) game = 't';
     if (game == 't')
        {cout << "Tie Game." <<endl; return game; };
      

          
     
     
     
     return game;        
}// end funtion checkWinner

//Checks to see if the position is taken     
bool ticTac::checkPosn(int spot, char player)
{
 
     if (posn[spot] == 'x' || posn[spot] == 'o'){
          cout << "Position already taken, please choose another position." <<endl;
          system ("pause");
          return true;
          }
          else {
                    posn[spot] = player;
                    cout << "Nice move." <<endl;
                    system ("pause");
                    counter++;
                    return false;
                   
          }
 
     
 
     return false;
 
}// end funtion checkPosn

//Tells the next player that it's thier turn
void ticTac::nextPlayer()
{
     if (player == 'x')
         player = 'o';
     else player = 'x';
     return;
}// end funtion nextPlayer

//This switches between players         
char ticTac::getPlayer()
{
     return player;
}// end funtion getPlayer

Edited 7 Years Ago by peter_budo: Correcting code tags, please use it as [code]YOUR CODE HERE[/code]

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