Inquiry about class variable declarations in C++

Question

I have a class to represent a 3D vector of floats:

class Vector3D
{
    public:

    float x, y, z;
    float * const data;

    Vector3D() : x(0.0), y(0.0),         


        

Answer 1

Do something like this:

float data[3];
float& x, y, z;

    Vector3D() : x(data[0]), y (data[1]), z(data[2]) { data [0] = data [1] = data [2] = 0;}