'no operator "=" matches these operands' in C++

I am attempting to make a board object for a tic tac toe game, and can’t get around this error.

class Board {
    public:
        void reset() {
            board[3][3] = {
                {" ", " ", " "},
                {" ", " ", " "},
                {" ", " ", " "}
            };
        };

    private:
        std::string board[3][3];

    Board() {
        reset();
    };
        
};

I’ve tried switching the variable type from std::string to char but it throws a different error which makes no sense either

>Solution :

I think you may have an issue with your reset() method of the Board class. It’s trying to change the value of the board member variable (of type String[][]) using the = operator which is not possible because arrays are not assignable in C++.

There are two fixes that I see for this issue:

the fix I would use (if you want to keep the same vibe of your code) is to loop over every value in the board and set the strings individually to " " like this:

for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
        board[i][j] = " ";
    }
}

changing the class to look like this:

class Board {
public:
    void reset() {
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                board[i][j] = " ";
            }
        }
    };

private:
    std::string board[3][3];

    Board() {
        reset();
    };
};

However, if you are looking for something more modern, I’d recommend the C++ std::array instead of a raw array. Utilizing the std::array would give you access to the built-in fill() method (i.e. std::array::fill) to initialize the array as follows:

#include <array>
#include <string>

class Board {
public:
    void reset() {
        board.fill(" ");
    };

private:
    std::array<std::array<std::string, 3>, 3> board;

    Board() {
        reset();
    };
};