Inheriting functions and adding to them

[strongdrink]

Hello,

How would I go about inheriting a function and changing it?
Here is what I have so far..

...Code here...

class Item {

  protected:
  
  ...a bunch of variables...
  
  public:
    
  ...a bunch of functions here...
  
  //Magic
  void Draw ();
  
};

void Item::Draw () {
  
  ...operations...

}

class File: public Item {

  public:

  void Draw ();

};

void File::Draw () {

  Item::Draw();

  ...operations to add to Item::Draw...

}

Item *items[32000];
items[0] = new File();

...More code here...

items[0]->Draw();

...Rest of program...

What I get from the above code, is that the Item::Draw function works.. but it doesn't add the File stuff..

Thanks!

P.S.

If you want all of the code I can send a link. (too much to post here :S)

[LB]

You need to make the Draw function in the Item class virtual.
http://www.cplusplus.com/forum/general/44630/#msg241726

[zwA4jE8b]

Maybe I'm just inexperienced but... you create and array of Item pointers but you assign a 'File' object to be pointed to.
seems like that would be like writing char *ch = new int;

should it not be

File *items[32000];
items[0] = new File();

[strongdrink]

@L B

thanks

@ CreativeMFS

no, because there are more classes than just "File" that I also want to group in that array

[LB]

@CreativeMFS: You need to read up on polymorphism and inheritance ;)
http://www.cplusplus.com/doc/tutorial/polymorphism/