2D Char Array中出现奇怪的字符

Question

I'm coding a game that utilizes a 'grid', which I have created using a 2 dimensional array of structs, which contain a char value and a boolean value. In my program's .h file, I declare the struct and create the grid.

struct Tile
{
    char letter;
    bool active;
};

Tile grid [6][5];

In my .cpp file, I initialize the grid so that all values are blank.

 for (int i = 0; i < 7; ++i)
    {
        for (int j = 0; j < 6; ++j)
        {
            grid[i][j].active == false;
            //grid[i][j].letter = '.';
            //it always crashes when i try doing the above line
        }

    }

The function that prints the grid, printGrid, is below

for (int i = 0; i < 7; ++i)
    {
        for (int j = 0; j < 6; ++j)
        {
            cout << i;
            //the above statement is for debugging purposes so that I can see
            //which column easier
            std::cout << grid[i][j].letter;
        }
        std::cout << std::endl;
    }
    cout << "1 2 3 4 5 6" << endl;

Now, the original goal was to have the default .letter value be '.'. But for some reason, when I tried to do this, there are disastrous results; the screen fills up with characters moving so fast I can't entirely see what they are (I recall some hearts and smiley faces), along with an obnoxious, rapid beeping. So I decided to leave that commented line out.

When I run the program without that line, for some reason, the "grid" always displays characters in certain spots, without any input from the user, or without me having expressly declared any values to that spot. For instance, the spot of the 1st column from the left and the bottom row, always has a character in it (grid[6][5].letter). It changes every time I run the program, and I've seen it range from a heart, to the letter A, to the spanish 'n' (the one with a ~ over it).

I thought to myself, "Hey, since grid[6][5] is the spots that are always buggy, I'll just declare those individual spot's .letter values to be blank (' ')!". That didn't work.

I've got no idea why this one spot is giving me trouble. There were other areas that would have an abnormal character, but I was able to neutralize them by setting their .letter values to blank. If anyone has any idea on how to fix this, pleas

EDIT: The other abnormal characters, which appear at grid[6][0], grid[6][1], grid[6][5], and grid[6][4], all make my program crash at later stages if I set them to blank (' '); however, blanking grid[6][5] is the one that makes it crash at the get go. I tried using a debugger, but it wasn't able to tell me anything helpful.

Answer 1

you're running over the end of your arrays

Tile grid [6][5]; needs to be Tile grid [7][6];

or you need to loop only to i < 6 and j < 5 .