Note: I asked this question on TopAnswers a couple weeks ago, but didn't get any response, so I figured I'd ask it here.

I am currently learning C++. I have a parent class (Vehicle) and two subclasses (Car and Boat). I am wondering how to create an object that will either be Car or Boat, depending on what the user specifies.

Below is my best attempt. It compiles and runs, but doesn't do what I want. It is supposed to make *vh a Car or Boat, but *vh always remains a Vehicle.

#include <iostream>

using namespace std;

class Vehicle
{
	public:
		void print(void)
		{
			cout<<"this is a vehicle\n";
		}
};

class Car: public Vehicle
{
	public:
		void print(void)
		{
			cout<<"this is a car\n";
		}
};

class Boat: public Vehicle
{
	public:
		void print(void)
		{
			cout<<"this is a boat\n";
		}
};

int main()
{
	Vehicle *vh = new Vehicle();
	Car *cr = new Car();
	Boat *bt = new Boat();

	int x;
	cout<<"type 0 for car and 1 for boat: ";
	cin>>x;

	if(x==0)
	{
		cout<<"you chose car\n";
		vh = cr;
	}
	else if(x==1)
	{
		cout<<"you chose boat\n";
		vh = bt;
	}
	vh->print();
}

posted almost 2 years ago

CC BY-SA 4.0

2y ago by Alexei‭

Trevor‭

169 reputation 5 1 28 5