Question

If I have a pointer that is pointing somewhere in a string, let’s say it is pointing at the third letter (we do not know the letter position, basically we don’t know it is the third letter), and we want it to point back to the first letter so we can make the string to be NULL how do we do that?

For example:

if we have ascii as a pointer
ascii is pointing now somewhere in the string, and i want it to point at the first char of the string how do i do that?

(Note:
I tried saying

int len = strlen(ascii);
ascii -= len;
ascii = '0';

but it is not working, it changes wherever the pointer is to 0 but not the first char to 0)

Answer 1

You cannot. C and C++ go by the “no hidden costs” rule, which means, among other things, noone else is going to secretly store pointers to beginnings of your strings for you. Another common thing is array sizes; you have to store them yourself as well.