Operator Overloaded for Array but not working in Main-CodePudding

I wrote a program to add, subtract and multiply two matrices together. I overloaded the operators , -, and * for this purpose, but when I use them in the main, I get an error which says:

no operator " " matches these operands I can't figure out the problem. Maybe I used incorrect logic to overload the operators for class and now I'm stuck with it. The Code is below

#include <iostream>
#include <conio.h>
#include <string>
#include <ctime>

using namespace std;

class ERROR
{
public:
    string E = "Number of Columns of Matrix A is not Equal to Number of Rows of Matrix B";
};
class MATRIX
{
private:
    static const int number = 100;
    int matrix[number][number];
    int n; 
    int m;
public:
    MATRIX();
    MATRIX(int,int);
    void display();
    MATRIX operator (MATRIX x[]);
    MATRIX operator-(MATRIX x[]);
    MATRIX operator*(MATRIX x[]);
    MATRIX operator=(MATRIX x[]);
};

int main()
{
    srand(time(0));
    MATRIX x(2, 2), y(2, 2);
    cout << "Matrix 1 " << endl;
    x.display();
    cout << endl;
    cout << "Matrix 2 " << endl;
    y.display();
    cout << endl;
    MATRIX z(2, 2);
    z = x   y;
}


// Constructors of Class Matrix

MATRIX::MATRIX()
{
    n = number; m = number;
    for (int loop = 0; loop < number; loop  )
    {
        for (int loop2 = 0; loop2 < number; loop2  )
        {
            matrix[loop][loop2] = 1   rand() % 50;
        }
    }
}

MATRIX::MATRIX(int rows, int col)
{
    n = rows; m = col;
    for (int loop = 0; loop < n; loop  )
    {
        for (int loop2 = 0; loop2 < m; loop2  )
        {
            matrix[loop][loop2] = 1   rand() % 50;
        }
    }
}

// Display function for Class

void MATRIX::display()
{
    for (int loop = 0; loop < n; loop  )
    {
        for (int loop2 = 0; loop2 < m; loop2  )
        {
            cout << matrix[loop][loop2] << " ";
        }
        cout << endl;
    }
    cout << endl;
}

// Operators Overloaded for Array

MATRIX MATRIX::operator (MATRIX x[])
{
    MATRIX z(n,m);
    for (int loop = 0; loop < n; loop  )
    {
        for (int loop2 = 0; loop2 < m; loop2  )
        {
            z.matrix[loop][loop2]= matrix[loop][loop2]   x->matrix[loop][loop2];
        }
    }
    return z;
}
MATRIX MATRIX::operator-(MATRIX* x)
{
    MATRIX z(n, m);
    for (int loop = 0; loop < n; loop  )
    {
        for (int loop2 = 0; loop2 < m; loop2  )
        {
            z.matrix[loop][loop2] = matrix[loop][loop2] - x->matrix[loop][loop2];
        }
    }
    return z;
}
MATRIX MATRIX::operator*(MATRIX x[])
{
    try
    {
        if (m == x->n)
        {
            MATRIX *y[number][number];
            for (int loop = 0; loop < n; loop  )
            {
                for (int loop2 = 0; loop2 < m; loop2  )
                {
                    for (int loop3 = 0; loop3 < m; loop3  )
                    {
                        y[loop][loop2]  = matrix[loop][loop3] * x->matrix[loop3][loop2];
                    }
                }
            }
            return *this;
        }
        throw;
    }
    catch (ERROR e)
    {
        cout << e.E << endl;
        _getch();
        exit(1);
    }
}

MATRIX MATRIX::operator=(MATRIX x[])
{
    for (int loop = 0; loop < n; loop  )
    {
        for (int loop2 = 0; loop2 < m; loop2  )
        {
            matrix[loop][loop2] = x->matrix[loop][loop2];
        }
    }
    return *this;
}

CodePudding user response：

You've defined the operator between a MATRIX and a MATRIX[] (i.e., an array of MATRIXs). You should amend the definition to operate on a MATRIX and another MATRIX:

MATRIX operator (MATRIX x);

and of course, amend the implementation accordingly.

EDIT:
As Fabien mentioned in the comments, using a const reference will save copying the second operand when using this operator:

MATRIX operator (const MATRIX& x);