CODEWITHSUNDEEP
c++
jmasterx
jmasterx

Reputation: 54113

Constructors and inheritance?

Lets say I have a class named Car and another which inherits from Car called SuperCar. How can I ensure that Car's costructor is called in SuperCar's constructor? Do I simply do: Car.Car(//args);?

Thanks

Upvotes: 4

Views: 310

Answers (6)

kriss
kriss

Reputation: 24177

In SuperCar constructor add : Car(... your arguments ...) between constructor header and constructor body.

Exemple with code:

#include <iostream>
using namespace std;

class Car {
    public:
    Car() { }
    // Oh, there is several constructors...
    Car(int weight){
        cout << "Car weight is " << weight << endl;
    }
};

class SuperCar: public Car {
    public:
    // we call the right constructor for Car, detected by call arguments
    // relying on usual function overloading mechanism
    SuperCar(int weight, int height) : Car(weight) {
        cout << "SuperCar height " << height << endl;
    }
};

int main(){
    SuperCar(1, 10);
}

PS: By the way calling SuperCar a subclass of Car is confusing, you should probably avoid that.

Upvotes: 3

liaK
liaK

Reputation: 11648

Your SuperCar constructor will be like,

SuperCar(int sayForExample):car(sayForExample),m_SuperCarMember(sayForExample)
{
 // constructor definition
}

This will invoke the specific constructor car(int) and initialize the SuperCar's member m_SuperCarMember..

Hope it helps..

Upvotes: 1

aJ.
aJ.

Reputation: 35450

You can do this using initialiser list.

SuperCard::SuperCar(args):Car(args){ //Supercar part}

Upvotes: 0

Steve Townsend
Steve Townsend

Reputation: 54148

On your derived class constructor, define an initializer for the base class with the required parameters:

SuperCar(/*params*/) : Car(/*differentParams*/)
{
}

Upvotes: 1

DumbCoder
DumbCoder

Reputation: 5766

Sample classes with no member vars.

class Car { 
            Car(); /*If you want default objects*/
            Car(/*arg list*/); /* maybe multiple constructors with different, count and 
                                type args */
};

class SuperCar {
           SuperCar(/*args list*/) : Car(/*arg list*/){/*Constructor Body*/}
};

Upvotes: 5

fancyPants
fancyPants

Reputation: 51868

example:

SuperCar::SuperCar(Parameter p) : Car(p){
   //some voodoo...
}

if i remember correctly

edit: damn, kriss was faster :)

Upvotes: 3

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