Passing by reference in C

Question

If C does not support passing a variable by reference, why does this work?

#include 

void f(int *j) {
  (*j)++;
}

int main() {
  int i = 20;         


        

Answer 1

p is a pointer variable. Its value is the address of i. When you call f, you pass the value of p, which is the address of i.