Question

I’m not sure really what to search for to try and find my answer, so please redirect me to any relevant articles and I apologize in advance.

I’m really new to C++ and am trying to make a 3×3 CLI Tile game. I can assign the Tile objects to the private array of pointers in the TileGame constructor and see they have valid memory addresses (or so I think.) My problem is when I run a method to try and access that data. It looks like the the first element in the array has a value, but the others look very odd. I’m sure it’s something small, but I’m at a loss as to what I’m doing wrong. I’ve also tried creating an accessor method, but that only seemed to complicate things.

#include <iostream>
using namespace std;

class Tile
{
    private:
        int position;
        int tileID;
    public:
        Tile(int, int);
};

// tile constructor
Tile::Tile(int p, int id) : position(p), tileID(id) {}

class TileGame
{
    private:
        const int MAX_TILES;
        Tile* tiles[];
    public:
        TileGame();
        void shuffle();
};

// game constructor
TileGame::TileGame() : MAX_TILES(8)
{
    Tile* tiles[MAX_TILES];
    for (int i = 0; i < MAX_TILES; i++)
    {
        tiles[i] = new tile(i, i);
    }

    // spit out the addresses for each
    cout << endl << "From TileGame(): " << endl;
    for (int i = 0; i < MAX_TILES; i++)
    {
        cout << tiles[i] << endl;
    }
}

void TileGame::shuffle()
{
    // spit out the addresses for each
    cout << endl << "From TileGame(): " << endl;
    for (int i = 0; i < MAX_TILES; i++)
    {
        cout << tiles[i] << endl; // <-- This seems to be the problem
    }
}

int main()
{
    TileGame* game = new TileGame();
    game->shuffle();
}

This should compile (I had to retype it, so I hope I didn’t make mistakes.) The output that I get is something like:

From TileGame():
0x7f9349c03aa0
0x7f9349c03ab0
0x7f9349c03ac0
0x7f9349c03ad0
0x7f9349c03ae0
0x7f9349c03af0
0x7f9349c03b00
0x7f9349c03b10

From shuffle():
0x7fff9502752c
0x100
0
0
0
0
0
0

I arrived at this point when I kept getting seg faults by trying to access tiles[] values. Thoughts?

Answer 1

The tiles array that is created in the constructor of TileGame is not the tiles array in the Game object. Get rid of the one in the constructor.

Also, too may pointers. The tiles array can hold Tile objects; no need for the indirection and the news. Similarly, there’s no need for game to be a pointer. Just create it as a TileGame object.