Maths Question

[Nuvo]

I'm pretty sure NULL is declared as binary zero in stdio.h isn't it?. It is (I just checked in Visual Studio), and a NULL pointer is declared as ((void *)0.

[Dan]

It's not conceptually the same thing, though. NULL might happen to be represented by 0 on a specific platform, but it doesn't have to be.

There are platforms where 0 is a perfectly valid memory address and therefore makes for a pointer having that value to be called NULL.

That's the reason it's declared as a constant and then that constant used, rather than directly using 0. Ideologically, NULL is the complete absense of value, but since a physical bit has to be on or off (it can't be neither - at least not in binary computing, quantum computing is a totally different ballgame) we have to pick a real value to represent NULL.

Plus that's only when we're dealing on a low level. NULL certainly isn't the same thing as 0 to .NET managed code, PHP code or any database system. In fact, most SQL gurus would have a heart attack if you even suggested they were the same thing

</geekery>

Let's go drive some cars

[Nuvo]

Agreed. Let's leave it there.