C++ 2d array writing into multiple places

Question

I'm trying to write a console C++ chess game and whenever I write into my board array at places like 07 it will put info in other places like 10.

I'm also getting buffer overruns warnings on Board[0][0] = 'C';

void Setup(char Board[7][7])
{
    // sets all board spaces to a period
    for (int a = 0; a < 8; ++a)
    {
        for (int b = 0; b < 8; ++b)
        {
            Board[a][b] = '.';
        }
    }

    //place pieces
    {
        Board[0][0] = 'C';
        Board[0][7] = 'C';
        Board[7][0] = 'c';
        Board[7][7] = 'c';
        Board[0][1] = 'H';
        Board[0][6] = 'H';
        Board[7][1] = 'h';
        Board[7][6] = 'h';
        Board[0][2] = 'B';
        Board[0][5] = 'B';
        Board[7][2] = 'b';
        Board[7][5] = 'b';
        Board[0][3] = 'Q';
        Board[0][4] = 'K';
        Board[7][3] = 'k';
        Board[7][4] = 'q';

        for (int p = 0; p < 8; ++p)
        {
            Board[1][p] = 'P';
            Board[6][p] = 'p';
        }
    }
    cout << "setup complete" << endl;
}

void Display(char Board[7][7])
{
    for (int a = 0; a < 8; ++a)
    {
        for (int b = 0; b < 8; ++b)
        {
            cout << Board[a][b] << " ";
        }

        cout << endl;
    }
}

int main()
{
    static char Board[7][7];
    int Winner = 0;

    Setup(Board);
    while (Winner == 0)
    {
        //turn1
        //turn2
        Display(Board);
        break;
    }
    //winner
    return 0;
}

this outputs:

setup complete
C H B Q K B H P
P P P P P P P P
P . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . p
p p p p p p p p
p h b k q b h c

The pawns are never written into place like 07 but somehow they show up there. Honestly I have no idea what I'm doing wrong.

Answer 1

The problem is considering Baord as 7x7 array. In provided code char Board[7][7] should be char Board[8][8].

Keep in mind the following, while you are working with array:

• Declaration/Definition: When you declarer/define an array at that time the value in [] is size of the array. e.g. int testArray[10]; Here we defined an array of size 10 which have index from 0 to 9
• Operation on array elements: When you try to use the array and perform some operation, the the value in [] is index in the array. e.g. testArray[5] = 20; Here we have changed the value of 6th element(which is at index 5 as index starts from 0 and from 1) to 20.
• Element and index: As mention in above lines, Index in array starts from 0. So 1st element will be at index 0, 2nd at index 1 and so on i.e. Nth element will be at index N-1

Following is corrected code. you can see it working here:

#include <iostream>
#define ARRAY_SIZE 8
using namespace std;

void Setup(char Board[ARRAY_SIZE][ARRAY_SIZE])
{
    // sets all board spaces to a period
    for (int a = 0; a < ARRAY_SIZE; ++a)
    {
        for (int b = 0; b < ARRAY_SIZE; ++b)
        {
            Board[a][b] = '.';
        }
    }

    //place peices
    {
        Board[0][0] = 'C';
        Board[0][7] = 'C';
        Board[7][0] = 'c';
        Board[7][7] = 'c';
        Board[0][1] = 'H';
        Board[0][6] = 'H';
        Board[7][1] = 'h';
        Board[7][6] = 'h';
        Board[0][2] = 'B';
        Board[0][5] = 'B';
        Board[7][2] = 'b';
        Board[7][5] = 'b';
        Board[0][3] = 'Q';
        Board[0][4] = 'K';
        Board[7][3] = 'k';
        Board[7][4] = 'q';

        for (int p = 0; p < ARRAY_SIZE; ++p)
        {
            Board[1][p] = 'P';
            Board[6][p] = 'p';
        }
    }
    cout << "setup complete" << endl;
}

void Display(char Board[ARRAY_SIZE][ARRAY_SIZE])
{
    for (int a = 0; a < ARRAY_SIZE; ++a)
    {
        for (int b = 0; b < ARRAY_SIZE; ++b)
        {
            cout << Board[a][b] << " ";
        }

        cout << endl;
    }
}

int main()
{
    static char Board[ARRAY_SIZE][ARRAY_SIZE];
    int Winner = 0;

    Setup(Board);
    while (Winner == 0)
    {
        //turn1
        //turn2
        Display(Board);
        break;
    }
    //winner
    return 0;
}

Answer 2

When you create an array:

    int foo[4];

the number 4 means you will have 4 ints, which you can access using:

    foo[0]
    foo[1]
    foo[2]
    foo[3]

So when you create char Board[7][7] with two sevens, you get a 7x7 chess board (because 0, 1, 2, 3, 4, 5 and 6 are 7 numbers in total, not 8), and therefore not a 8x8 chess board.

So just replace any Board[7][7] by Board[8][8] and you will be fine.