C++ Class Definition model parking lot

#include <iostream>
using namespace std;
#include <conio.h>
const char ESC = 27;           //escape key ASCII code
const double TOLL = 0.5;       //toll is 50 cents
class ParkingLot/*from w  w  w.  j a  va2 s  .  c om*/
{
   private:
   unsigned int totalCars;  //total cars passed today
   double totalCash;        //total money collected today
   public:                     //constructor
   ParkingLot() : totalCars(0), totalCash(0.0)
   {  }
   void payingCar()                       //a car paid
   { totalCars++; totalCash += TOLL; }
   void nopayCar()                        //a car didn't pay
   { totalCars++; }
   void display() const                   //display totals
   { 
       cout << "\nCars=" << totalCars << ", cash=" << totalCash << endl; 
   }
};
int main()
{
   ParkingLot booth1;           //create a toll booth
   char ch;
   cout << "\nPress 0 for each non-paying car," << "\n      1 for each paying car," << "\n      Esc to exit the program.\n";
   do {
      ch = getche();           //get character
      if( ch == '0' )          //if it's 0, car didn't pay
         booth1.nopayCar();
      if( ch == '1' )          //if it's 1, car paid
         booth1.payingCar();
   } while( ch != ESC );    //exit loop on Esc key
   booth1.display();           //display totals
   return 0;
}