How do I initialize the size of an array of pointers in a function?

Question

I've tried two different things, but I'm not entirely sure what is happening. Looking for an explanation and input on how to do this in the best possible way, thanks! I don't want to use a vector.

Graph.h

public:
   void setNodeList(int num);
private:
   Node *nodeList[];

Graph.cpp

void Graph::setNodeList(int num)
{
   nodeList[num]; // Would this work?
   *nodeList = new Node[num]; // Or this? Not really sure.
}

Use `std::vector` – StoryTeller - Unslander Monica Nov 20 '17 at 06:17 — StoryTeller - Unslander Monica, Nov 20 '17 at 06:17

score 0 · Answer 1 · answered Nov 20 '17 at 06:27

If you want that your array is situated on the heap ("permanently" stored, and removed after the methods returns), then you should use

*nodeList = new Node[num];

Be aware to delete your allocated memory via delete[] nodeList and NOT via delete nodeList (without []). This stackoverflow answer explains why.

As @StoryTeller suggests I would also check the STL std::vector, which represents a dynamic collection.

How do I initialize the size of an array of pointers in a function?

1 Answers1