Here is what the maps look like:

class World {
  int sum;
  int value;
 
  // value |-> int, sum |-> int
 
  void add(int foo) {
    // foo |-> int, value |-> int, sum |-> int
    string z;
    // z |-> string, foo |-> int, value |-> int, sum |-> int
    sum = sum + value;
    value = 0;
  }
 
  // value |-> int, sum |-> int
 
  void main(string bar) {
    // bar |-> string, value |-> int, sum |-> int
    int y;
    // y |-> int, bar |-> string, value |-> int, sum |-> int
    sum = 0;
    value = 10;
    add();
    // y |-> int, bar |-> string, value |-> int, sum |-> int
    if (sum % 3 == 1) {
      string value;
      // value |-> string, y |-> int, bar |-> string, (((value |-> int))), sum |-> int
      value = 1;
      add();
      print("inner value = ", value);
      print("sum = ", sum);
    }
    // y |-> int, bar |-> string, value |-> int, sum |-> int
    print("outer value = ", value);
  }
}

• Note how the outer declaration of int value is shadowed by the inner declaration of string value
• Note how map becomes bigger as we enter more scopes, but later becomes smaller again
• If we processed statements sequentially imperatively, we need to make maps bigger and later smaller again
  • alternatively we can use functional programming style and keep the old version until it is needed again