c# Multi-Dimensional Array verification

Question

I´m trying to read the array below. What i want to do is just verify if the number 1 and 2 exists at the same time in the array. The problem is with my method. I keep getting an "use of unassigned local variable 'jogavel1'", that is inside my method. Can someone help or explain what i am doing wrong? Thanks a lot for your participation =).

        int[,] tabuleiro = new int[8, 8] {
            {1, 0, 1, 0, 1, 0, 1, 0},
            {0, 1, 0, 1, 0, 1, 0, 1},
            {1, 0, 1, 0, 1, 0, 1, 0},
            {0, 0, 0, 0, 0, 0, 0, 0},
            {0, 0, 0, 0, 0, 0, 0, 0},
            {0, 2, 0, 2, 0, 2, 0, 2},
            {2, 0, 2, 0, 2, 0, 2, 0},
            {0, 2, 0, 2, 0, 2, 0, 2},
        };

        int numero = verificar(tabuleiro);

        Console.ReadKey();
    }


    public static int verificar(int[,] tabuleiro) {
        int jogavel, jogavel1, jogavel2 = 0;
        for (int i = 0; i < 7; i++) {
            for (int a = 0; a < 7; a++) {
                if (tabuleiro[i, a] == 1) {
                    jogavel1++;
                }
                else if (tabuleiro[i, a] == 2) {
                    jogavel2++;
                }
            }
        }
        if (jogavel1 > 0 && jogavel2 > 0) {
            jogavel = 1;
        }
        else
            jogavel = 0;
        return jogavel;
    }
}

Answer 1

Your variable instantiation is the problem:

int jogavel, jogavel1, jogavel2 = 0;

Doing it this leads to only having jogavel2 being assigned a value. Instead you should assign them like this:

int jogavel; // in your case this variable doesn't necessarily needs to be assigned
int jogavel1 = 0;
int jogavel2 = 0;

Explanation: Within your for-loop you use jogavel1 and jogavel2 and increment them using the ++-operator. This isn't possible for unassigned variables, which applies to jogavel1. On the other hand jogavel doesn't necessarily needs to be assigned a value to as you don't use it for a direct calculation. Instead you just assign a value to it in your if-else-statement, which is fine for the compiler.

By the way there's an error in your logic: Within your loops you don't fetch the last elements from the array. You use i < 7 resp. a < 7 as a break condition, which is not correct as your jagged array has 8 elements in each dimension. So you better edit it like this:

...
for (int i = 0; i < tabuleiro.GetLength(0); i++) // array-length of 1. dimension (=8)
{
    for (int a = 0; a < tabuleiro.GetLength(1); a++) // len. of 2. dimension (=8)
    ...

Answer 2

Local variables aren't initialized. You have to manually initialize them.

So you code should be

int jogavel, jogavel1=0, jogavel2 = 0;