What does a pointer exactly pull to when you make it "null

[jinjin12]

When you make a pointer point to "null" making the head of the last element of a linked list point to "null", is that is that pointer actually pointing to? some random location in memory?

[CodeGoggles]

It isn't pointing to any memory. Or perhaps a reserved piece of memory specifically allocated for a null pointer. Honestly I'm not sure but you can be sure you wont corrupt any data, if you try to access the value of a null pointer it will crash your program.

[Lachlan Easton]

Let me explain with this simple graphic https://lh3.googleusercontent.com/-tjVfgN7GFP4/U31W5zx_TAI/AAAAAAAAN5c/yjRRNx0zwxY/w920-h690-no/20140522_114508.jpg

[jinjin12]

lachlan but what does it mean to point to nothing? the pointer has to point to something, it can't point to "nothing"? what is "null" exactly? is it a place in memory?

I read somewhere that a pointer pointing to null means it's pointing to a zero-th position in memory that is OS reserved?

[Disch]

I read somewhere that a pointer pointing to null means it's pointing to a zero-th position in memory that is OS reserved?

This is more or less correct.

A pointer just contains an address.

Different addresses can refer to different things (often memory, but maybe also a hardware register or something). Address 0 is set aside for "nothing", so the address goes nowhere, or simply goes somewhere that your program cannot access.

[Lachlan Easton]

the pointer has to point to something

No, that is the point of a null pointer, it doesn't point anywhere. It's like handing up a blank envelope and asking "Who is this addressed to?", it's not addressed to anyone.