Parking system implementation using Classes Test Question

[A55a551n]

I just gave my online test and this question was given to us.

I used an function in which an array returns true when it is empty and returns false when it's full.

You are supposed to make a software that manages Parking lots. Vehicles get parked in a Parking lot. Each vehicle has a registration number, manufacturer and model. Vehicle can either be a car or a bike. In addition to above attributes Car also has number Of doors.

Following is part Of the code used in the Software.
Please go through it and answer the questions that follow:

#include "Vehicle. h"
class ParkingLot
public:
ParkingLot( int size);
//returns true if parking slot was available, false otherwise

bool park(Vehicle*);
Vehicle** getParkedVehicles();
int getNum_of_slots();
private:
int numof_slots;
Vehicle** parkedvehicle;
}

int main()
{
ParkingLot new ParkingLot(30);
car *corolla1 = new Car( "LOX 213", "Toyota","corolla", 4);
bike* honda1 = new Bike("LED 2179", "Honda", "CD70");
fastParking->park(corolla1);
fastParking->park(honda1);
int num=fastParking->getNum_of_slots();
Vehicle ** vehicles= fastParking->getParkedVehicles();
for(int i=0; i<num; i++)
{
/*the display() method displays registration number, manufacturer and
model in case of bike and in case of car it displays all Of above as well
as number Of doors*/
if(vehicles[i]!=0)
cout<<"Parking slot"<<i+1<<"has"<<vehicles[i]->display();
else
cout<<"Parking slot"<<i+1<<"is empty"<<endl;
}
return 0;
}

Q:Implement the park method Of the ParkingLot class.

[salem c]

We're not here to do your homework.
http://www.catb.org/esr/faqs/smart-questions.html#homework

Format your code properly if you want people to read it.
https://www.cplusplus.com/articles/jEywvCM9/
Honey attracts better than vinegar.

[A55a551n]

Bro
I submit it through a mobile.
My pc is dead and due to the lock down i can't program

[Ganado]

Perhaps you meant
ParkingLot* fastParking = new ParkingLot(30);
You also have memory leaks because you never delete anything you new.

It would be better to just do:

ParkingLot fastParking;
// ...
fastParking.park(corolla);

[A55a551n]

I can't figure out what's causing the error

#include <iostream>
#include <string>
using namespace std;


class Vehicle
{
public:
  string RN;
  string manufacturer;
  string model;

  Vehicle()
  {
    RN="";
    manufacturer="";
    model="";
  }
  void setVehicle(string a,string b, string c)
  {
    RN=a;
    manufacturer=b;
    model=c;
  }
  virtual void display();

};
class ParkingLot
{
public:
ParkingLot( int size)
{
  numof_slots=size;
}

// returns true if parking slot was available, false otherwise
bool park(Vehicle*)
  {
  int count = 0;
  for  (int i = 0; i < numof_slots; i++)
  {
    if (parkedVehicles[i] == 0)
    {count++;
    return true;}
    
    else
    {return false;}
  }
  if (count > 0)
  {
    return true;
  }
   }

Vehicle **getParkedVehicles()
{
  return parkedVehicles;
}
int getNum_of_slots()
{return numof_slots;}
private:
int numof_slots;
Vehicle** parkedVehicles;
};

class Car:public Vehicle
{
private:
  int NOD;
public:
  Car():Vehicle()
  {NOD=0;
  }
  Car(string a,string b,string c,int d)
  {
    setVehicle(a,b,c);
    NOD=d;
  }
 virtual void::display()
  {
    cout<<"Bike :"<<endl;
    cout<<"Registeration number = "<<RN<<endl;
    cout<<"Manufacturer = "<<manufacturer<<endl;
    cout<<"model = "<<model<<endl;
    cout<<"Number of doors = "<<NOD<<endl;
  }
};

class Bike:public Vehicle
{
private:
       
  
public:
  Bike():Vehicle()
  {
    
  }
  
    
  
  Bike(string a,string b,string c)
  {
    setBike(a,b,c);
  }
  void setBike(string a, string b, string c)
  {
    setVehicle(a,b,c);
  }
  virtual void::display()
  {
    cout<<"Bike :"<<endl;
    cout<<"Registeration number = "<<RN<<endl;
    cout<<"Manufacturer = "<<manufacturer<<endl;
    cout<<"model = "<<model<<endl;
  }

};
int main()
{
ParkingLot *fastParking= new ParkingLot(30);
Car *corolla1= new Car("LOX 213", "Toyota", "Corolla", 4);
Bike* honda1= new Bike("LED 2179", "Honda", "CD70");

fastParking->park(corolla1);
fastParking->park(honda1);

int num=fastParking->getNum_of_slots();
Vehicle ** vehicles= fastParking->getParkedVehicles();

for(int i=0; i<num; i++)
{
/*the display() method displays registration number, manufacturer and
model in case of bike and in case of car it displays all of above as well
as number of doors*/
if(vehicles[i]!=0)
{
cout<<"Parking slot "<<i+1<< " has ";
vehicles[i]->display();
}
else
cout<<"Parking slot "<<i+1<< " is empty"<<endl;
}
return 0;
}

[Ganado]

What is the text of the error message?

virtual void::display()

This syntax looks wrong. If you're defining the function inline within the class definition, it would just be "virtual void display() { ... }".

Second, your indentation is very sloppy. Proper indentation makes the scope of logic clearer, and makes code easier to read.

[A55a551n]

Thx guys