How to use various function in c++

#A program that will you intruduce with some new function of c++.

1.  #include<iostream>
2.  using  namespace std;
3.  void  line(),massage();
    int main(){
4.  line();
5.  massage();
    cout<<endl<<"oh yes"<<endl<<"what a happy day"<<endl<<"oh what"<<endl<<"what a    nice day";
6.  return 0;  }
   
    void  line(){
    cout<<"oh what\n";  }
7.  void  massage(){cout<<"A happy day\n"<<endl;}