#include <iostream>
using namespace std;

// declaration
class vector {
    private:
        float x,y,z;

    public:
        void setVec(float a, float b, float c);
        void prtVec();
};// class vector

// definitions
void vector::prtVec() {
    cout << x << ", " << y << ", " << z << endl;
}// prtVec()

void vector::setVec(float a, float b, float c) {
    x=a;
    y=b;
    z=c;
}// setVec()

int main()
{
    vector v;
    v.prtVec(); // NOT been initialized!

    v.setVec(1,2,3);
    v.prtVec();

    return 0;
}// main()