An article about the null value of a pointer:

Bitesize Modern C++: nullptr

by Glennan Carnie

From the article:

What’s the value of a null pointer?

• 0
• NULL
• NUL

No doubt you’ve been involved in the (always heated) discussions about which is the correct one (By the way, if you said NUL you need to take yourself to one side and give yourself a stern talking to)...