Private Access

#include <iostream>
using namespace std;

class Sensor {
private:
   int rtn_value;
public:
   void setValue(int v) {rtn_value=v;}
   int getValue(){return rtn_value;}
};

int main() {
   Sensor s;
   s.setValue(75);
   cout << "Sensor value: " << s.getValue();
   return 0;
}