C++公共成员

#include <iostream>

using namespace std;

class line {
   public:
      double length;
      voID setLength( double len );
      double getLength( voID );
};

// Member functions deFinitions
double line::getLength(voID) {
   return length ;
}

voID line::setLength( double len) {
   length = len;
}

// Main function for the program
int main() {
   line line;

   // set line length
   line.setLength(6.0); 
   cout << "Length of line : " << line.getLength() <<endl;

   // set line length without member function
   line.length = 10.0; // OK: because length is public
   cout << "Length of line : " << line.length <<endl;

   return 0;
}