进程退出，返回值 3221226356

Question

I started to write simple class for matrix manipulation, one constructor fills a matrix with one number and other one takes 2d array as its argument.

    #include <iostream>

using namespace std;
int i,j;
class Matrica
{
public:
    Matrica(int, int, double);
    Matrica(int, int, double*);
    ~Matrica();
    void saberi(Matrica, Matrica);
    void read();
    void print();
private:
    int n,m;
    double* matrix;  
};

Matrica::Matrica(int a, int b, double broj)
{
    n = a;
    m = b;
    matrix = new double[n*m];
    for(i=0;i<n;i++) {
        for(j=0;j<m;j++) {
            matrix[i*n + j] = broj;
        }
    }
}

Matrica::Matrica(int a, int b, double* matr)
{
    n = a;
    m = b;
    matrix = new double[n*m];
    for(i=0;i<n;i++) {
        for(j=0;j<m;j++) {
            matrix[i*n + j] = matr[i*n +j];
        }
    }

}
Matrica::~Matrica() {
    delete[] matrix;
}

void Matrica::read() {
    double e;
    for(i=0;i<n;i++) {
        for(j=0;j<m;j++) {
            cout<< "insert element ["<<i<<"]["<<j<<"] :" <<endl;
            cin >> e;
            matrix[n*i +j] = e;
            cout<< endl;
        }
    }
}

void Matrica::print() {
    for(i=0;i<n;i++) {
        for(j=0;j<m;j++) {
            cout << matrix[n*i + j] << " ";
        }
        cout << endl;
    }
}
void Matrica::saberi(Matrica A, Matrica B) {
    cout << "foo";
}

int main()
{

    Matrica A(3,3,1);
    double K[3][3] = {{1,2,3},{4,5,6},{7,8,9}};
    Matrica B(3,3,&K[0][0]);
    Matrica C(3,3,7);
    C.saberi(A,B);
    return 0;
}

My program worked ok before I added empty "saberi" method which takes two objects as arguments. If I call it, my program crashes with 3221226356 return value. What could be wrong? Thanks in advance.

Answer 1

As you have defined your function signature

void saberi(Matrica, Matrica);

the Matrica objects there are passed by value, but you didn't provide a proper copy constructor for the class Matrica .

The easiest way to solve your current problem, is to pass the parameters by reference

void saberi(Matrica&, Matrica&);

or

void saberi(const Matrica&, const Matrica&);

Anyway, for the long term, you should either provide a proper copy constructor

Matrica(const Matrica&);

or forbid it (just put the declaration in the private section of the class).