C++ Member Initializer List

Caller.cpp

#include "Vector3.hpp"
#include <iostream>
using namespace std;

int main()
{
    Vector3 test;
    cout << "X=" << test.x << " Y=" << test.y << " Z=" << test.z << endl;
}

Vector3.cpp

#include "Vector3.hpp"
Vector3::Vector3() : x(1.0f), y(2.0f), z(3.0f)
{
}

Vector3.hpp

#ifndef VECTOR3_HPP
#define VECTOR3_HPP
class Vector3 
{
    public:
        float x,y,z;
        Vector3();
};

#endif