Memory Address

Relax. We'll talk through this in plain words — no textbook voice.

Every variable takes up a spot in computer memory, and that spot is called a memory address. In C you can actually see the address and store it in a pointer, which lets you study memory directly instead of just taking it on faith.

#include <stdio.h>

int main() {
  int myAge = 43;

  printf("Value: %d
", myAge);
  printf("Address: %p", (void *)&myAge);
  return 0;
}

&myAge returns the memory address of the myAge variable. %p is the output format for pointers/addresses.

You should see

Value: 43 Address: 0x7ffe5367e044

Info

The address value can change between computers and between runs, so don't expect your output to match exactly.

Easy traps

Don't print an address with the plain integer format %d. Use %p for pointer/address output.