+ - * /

Hi! I have a problem: VECTOR3D Vector2 = vB - vA; I would like this line to do this: Vector2.x =vB.x - vA.x; Vector2.y =vB.y - vA.y; Vector2.z =vB.z - vA.z; I saw in a code that a guy (DigiBen) used this: struct VECTOR3D { public: // A default constructor VECTOR3D() {} VECTOR3D(float X, float Y, float Z) { x = X; y = Y; z = Z; } // Here we overload the + operator so we can add vectors together VECTOR3D operator+(VECTOR3D vVector) { // Return the added vectors result. return VECTOR3D(vVector.x + x, vVector.y + y, vVector.z + z); } // Here we overload the - operator so we can subtract vectors VECTOR3D operator-(VECTOR3D vVector) { // Return the subtracted vectors result return VECTOR3D(x - vVector.x, y - vVector.y, z - vVector.z); } (....) float x, y, z; } Shall I always add a constructor?? If i do this in my code, i get a lot of errors from VC++. It asks for a constructor for each structure.. Can someone explain me?? Thanks a lot