What is a void pointer and what is a null pointer?

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The two concepts are orthogonal:

  1. A void pointer, (void *) is a raw pointer to some memory location.
  2. A null pointer is a special pointer that doesn’t point to anything, by definition. It can be a pointer to any type, void or otherwise.

A void pointer can be null or not:

void *void_ptr1 = nullptr;
void *void_ptr2 = malloc(42);
void *void_ptr3 = new Foo;               // void * can point to almost anything
void *void_ptr4 = (char*)void_ptr3 + 1;  // even somewhere inside an object

A non-void pointer can also be null or not:

Foo *f = nullptr;
Foo *g = new Foo;

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