[Suraine]

Dear c++ gurus, i have thk all over wat is means by the following hightlighted text, but not understood, can anyone explain to me what do they mean? or how do they function?

      class RotationSensor : public Sensor {
      public:

      RotationSensor(const Port port, int position = 0)
           : Sensor((Sensor::Port) port, true),
            rsensor((port == S1) ? ROTATION_1 :
           (port == S2) ? ROTATION_2 :
            ROTATION_3)
   
     #ifdef CONF_DSENSOR_VELOCITY
              ,
             rvelocity((port == S1) ? VELOCITY_1 :
                          (port == S2) ? VELOCITY_2 :
                          VELOCITY_3)
     #endif // CONF_DSENSOR_VELOCITY
       {
       on(); //! Turn on tracking of the sensor
       pos(position); //! Set the current position
       }
 
      ..........................................................
       }

How does the following function/run/do/etc?

RotationSensor(...) : Sensor (...), rsensor(...), rvelocity(...)
{
on();
pos(position);
}

wat does this block of codes represent? or do? or how it function?

Thanks guru.