Scope

1. Describe/write a simple program that demonstrates the usefulness of a static variable. This should be a "real" program not a "toy" program.
2. Consider the code below:

   // The main program
   var  x;
   function  sub1() {
     var  x;
     function  sub2() {
       . . .
     }
   }
   function  sub3() {
     . . .
   }
   

   Assume that the execution of this program is in the following unit order:
   • main calls sub1
   • sub1 calls sub2
   • sub2 calls sub3

    

   1. Assuming static scoping, in the following, which declaration of x is the correct one for a reference to x?
      • sub1
      • sub2
      • sub3
   2. Repeat part a, but assume dynamic scoping.

Lifetime

1. For each of the variables a - d, is the variable allocated statically or dynamically? Where is the variable stored? (Stack, heap, or global)

   int a;
   int main() {
       static int b;
       int c;
       int *d;
       d = malloc(sizeof(int)*3);
   }
   

2. When are each of the variables above deallocated?
3. Dynamic type binding is closely related to implicit heap-dynamic variables. Explain this relationship.

Updated Monday, 3 April 2023, 9:46 AM