/**
 * @file scopes_annotated.cpp
 * @author Jeffrey Bergamini for CS 19 Boot Camp, jeffrey.bergamini@cabrillo.edu
 *
 * Let's add *memory addresses* to the output to see which symbol `x` represents in which context.
 */

#include <iostream>

int x;  // global variable, global scope

void f1() {
  x = 2;  // assigns to global variable `x`
  std::cout << &x << '\t' << x << '\n';
}

void f2(int x) {
  std::cout << &x << '\t' << x << '\n';
  {
    int x;  // local variable (local to function `f1()`), scoped within anonymous block
    x = 4;  // assigns to local variable `x` scoped within anonymous block
    std::cout << &x << '\t' << x << '\n';
  }
  x = 5;  // assigns to local variable `x` (function parameter)
  std::cout << &x << '\t' << x << '\n';
}

int main() {
  x = 1;  // assigns to global variable (i.e., global var `x` is a *lvalue*)
  std::cout << &x << '\t' << x << '\n';
  f1();
  std::cout << &x << '\t' << x << '\n';  // function `f1()` should have mutated global variable `x`
  f2(3);
  std::cout << &x << '\t' << x << '\n';  // function `f2()` has not mutated global variable `x`
  int x;                                 // local variable, local scope
  x = 6;  // assigns to local variable `x` (global `x` is now "shadowed" for the rest of the block)
  std::cout << &x << '\t' << x << '\n';
}