CODEWITHSUNDEEP
c++arraysinheritancepointerssubclass
OVERTONE
OVERTONE

Reputation: 12187

inserting subclasses into a superclasses array in c++

This is one of those things where i just know im doing it wrong. My assignment is simple.

Create 3 classes in c++,

product ,software ,book. product is super, book and software are product. then make an array of pointers and fill the array with software and books.

so i've done the following

int main()
{
 Product *productList[10];          


 Book *pBook;                       
 Book q(5);
 pBook = &q;
 pBook->getPrice();

 Software *pSoftware;
 Software g(5);
 pSoftware = &g;
 pSoftware ->getPrice();


 productList[0] = pSoftware; // fill it with software, cannot do this.

Is there any way of inserting a subclass into a super classes array. Or should i define the array of pointers as something else.

class definitions below

class Product
{
public:

double price;

double getPrice();

Product::Product(double price){};
};


class Book: public Product
{
public:
Book::Book(double price)
    :Product(price)
{
}
double getPrice();
};

class Software: public Product
{
public:
Software::Software(double price)
    :Product(price)                 // equivalent of super in java?
{
}                                   // code of constructor goes here.
double getPrice();
};

Upvotes: 3

Views: 3133

Answers (4)

Sogger
Sogger

Reputation: 16132

Can't you just cast the software* to a product* to put it in your array? productList[0] = (Product*)pSoftware;

Upvotes: 0

ssmir
ssmir

Reputation: 1542

You should use public inheritance:

class Book : public Product {
...
};

[edit]

You should also declare getPrice() as virtual if you want to implement it differently in the child classes. This will make compiler call getPrice() of the right child class when you call getPrice() for a pointer to a Product:

virtual double getPrice();

Upvotes: 4

Falmarri
Falmarri

Reputation: 48577

It's been a while, but what's the default inheritance type in C++? Should

class Book:Product
{

be

class Book: public Product
{

It's always a good idea to be explicit anyway.

Upvotes: 0

Vijay Mathew
Vijay Mathew

Reputation: 27174

As the array is of type Product, you should declare pSoftware as a pointer to Product:

Product *pSoftware = new Software(5);
// ...
productList[0] = pSoftware;

Upvotes: 1

Related Questions