c++题目求助，第二个公有函数怎么写

class STU{
private:
    char name[20];
    double MA,PH,EG,Aver;
public:
    void Setsc(double x,double y,double z){
        MA=x;
        PH=y;
        EG=z;
        Aver=(x+y+z)/3.0;
    }
    double AVER(){ return Aver; }
    void print(){
        cout<<"MA="<<MA<<endl;
        cout<<"PH="<<PH<<endl;
        cout<<"EG="<<EG<<endl;
        cout<<"Aver="<<Aver<<endl;
    }

};

也可以类内声明，类外实现