I haven’t programmed in c++ for a while, and I was never a very good programmer to begin with. I’m trying to overload a ‘+’ operator for a class ‘MyVector’ that I am writing. Here’s the text for the header file “MyVector.h”:

class MyVector
{
public:
    double* data;
    MyVector();
    MyVector(int size);
    ~MyVector();

    void resize(int n);
    int SizeOfData;

    MyVector operator + (const MyVector&);
};

And here’s the function that doesn’t seem to work:

MyVector MyVector::operator + (const MyVector& vec)
{
    MyVector OutputSum(vec.SizeOfData); 

    if (vec.SizeOfData != SizeOfData)
    {
        cout << "Incompatible vector size!n";
       return *this;
    }
    
    for (int i = 0; i < SizeOfData; i++)
    {
        OutputSum.data[i] = vec.data[i] + data[i];
    }
    return OutputSum;
}

I tried running this using the following code:

int main()
{
    MyVector vec1(3);
    MyVector vec2(3);
    MyVector vec3(3);

    vec1.data[0] = 0;
    vec1.data[1] = 1;
    vec1.data[2] = 2;
    vec2.data[0] = 3;
    vec2.data[1] = 4;
    vec2.data[2] = 5;

    vec3 = vec1 + vec2;

    std::cout << vec3.data[0]<<" "<<vec3.data[1]<<" "<<vec3.data[2]<<"n";
    return 0;
}

But the program crashes after the ‘vec3 = vec1 + vec2″ line. For some reason although the overloaded operator function calculates the sum of vec1 and vec2, it returns nonsense, and then crashes. I can’t figure out why. What am I doing wrong?