5.2.3. Returning Values from Procedures

Try these first

1. 1.

   What does the Stack Pointer (SP) indicate?

   Hint

   Think about where data is temporarily kept in memory.

2. 2.

   Why do we save the Program Counter (PC) before calling a procedure?

   Hint

   Consider how the CPU knows where to continue execution.

3. 3.

   What is the purpose of the Stack Pointer (SP)?

   • To point to the current instruction
   • To point to the top of the stack
   • To store the main program address

   Hint

   Consider its role in stack management.

4. 4.

   True or False: The Program Counter (PC) is pushed onto the stack during a procedure call.

   • True
   • False

   Hint

   Reflect on what happens when procedures are invoked.

5. 5.

   Describe how the stack changes during two nested procedure calls. Illustrate with diagrams.

   Hint

   Sketch out the stack levels before and after each call.

6. 6.

   Discuss the implications of a stack overflow error. How can you prevent it when creating recursive procedures?

   Hint

   Reflect on how recursion needs to manage calls efficiently.