Inheritance and Arrays

[codegirl]

I have an abstract base class, call it ABC. It has two derived classes, say Derived1 and Derived2. In another class, I need an array of objects of either Derived1 or Derived2. The problem is I don't know if the array elements should be of type Derived1 or Derived2 until run time. (I have a variable called "mode", and the value of mode determines if the array should contain Derived1 or Derived2 objects.) I can't seem to create an array of ABC pointers since you can't create instances of an abstract class. So how can I create this array?

Thank you!!

 

[FurqanAhmed]

The problem here is that you must be making some mistake while declaring the ABC type pointer. It is possible to create pointers of abstract classes but you cannot create/instantiate objects of such classes. This means that you can use pointer of abstract classes for polymorphism.

ABC* abcPtr;
if(mode == 1)
abcPtr = new Derived1();
else
abcPrt = new Derived2();

try using the keywork "new" because it will dynamically create the object and return the pointer for the correct type. If the syntax might be wrong because I'm new to C++. Btw defering declaration of objects until runtime is called late binding or dynamic binding.

Furqan

YEH GHAZI YEH TERAY PUR-ASRAR BANDAY

 

[butthead]

please translate just out of curiosity

YEH GHAZI YEH TERAY PUR-ASRAR BANDAY

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