How can I change RAM values ​​in c/c++?

Question

C++ / C#

How can I read and write data to RAM using c/c++ on *unix systems?
What are there for this?

Answer 1

char *pointer = /* address in memory */
*pointer = 1;
According to the language standard, you have written this value to the memory location at this address.
According to the realities of modern programming - where did you get into? who gave you this memory? segfolt to you, not a bagel!...

Answer 2

Any value cannot be changed. Only those that belong to your process. This is the cornerstone of info-security for modern wasps.
For its memory - this is work with a pointer. You allocate a piece of memory for yourself through mallox / new and change what you need.