Thread: Null

Hi ! , just last question about NULL pointer and I really appreciate your effort.

what's still confusing me, is NULL pointer an constant address for every PC ? I mean we know that NULL pointer is 0x00000000000000 (depend 32bit or 64bit) , what I'm asking, is how will the PC know that this address "0x000000" is unique and not deferencing to any value? is that the management of the compiler to tell the PC that this address is NULL ?

Or maybe who made the architecture of the PC define that at address 0x0000 can't be deferencing pointer?



thanks alot and sorry for that question, but it's always plot up in my mind.

I know that in the compiler there's macro called NULL, but how really PC knows that this value can't be deferenced and it's void? ! is it defined in the architecture of the PC that at address 0x00000 can't be any dereferencing?