2.2.1a Programming constructs, recursion and variable scope Quiz: OCR Computer Science, Unit 7

The 20 questions

1. Which basic programming construct executes statements sequentially, one after the other?

   • Selection
   • Iteration
   • Recursion
   • Sequence

2. Which programming construct uses a condition to determine which branch of code to run?

   • Selection
   • Iteration
   • Sequence
   • Recursion

3. Which type of loop executes a block of code a predetermined number of times?

   • Infinite loop
   • Recursive loop
   • Condition-controlled
   • Count-controlled

4. What essential component of a recursive function stops it from calling itself indefinitely?

   • Stack frame
   • General case
   • Global variable
   • Base case

5. Where are return addresses and local variables stored during nested recursive calls?

   • Heap memory
   • Data segment
   • Call stack
   • Register file

6. What happens to a local variable when its function finishes executing?

   • Globalised
   • Retained
   • Deallocated
   • Paused

7. What type of scope allows a variable to be accessed from any function in a programme?

   • Global scope
   • Block scope
   • Dynamic scope
   • Local scope

8. When passing a parameter by value, what does the subroutine actually receive?

   • A local copy
   • The original variable
   • The memory address
   • A reference pointer

9. When passing a parameter by reference, what does the subroutine receive?

   • A local copy
   • The memory address
   • The return value
   • A duplicate constant

10. Which statement best describes a WHILE loop compared to a REPEAT UNTIL loop?

    • Pre-condition loop
    • Post-condition loop
    • Unconditional loop
    • Count-controlled loop

11. What error occurs when a recursive function fails to reach its base case?

    • Stack overflow
    • Type error
    • Syntax error
    • Null pointer

12. If a local variable shares a name with a global variable, which takes precedence inside the function?

    • The global variable
    • The local variable
    • Neither variable
    • The first declared

13. What is the output of func(3) for func(n): IF n==1 RETURN 1 ELSE RETURN n * func(n-1)?

    • 24
    • 6
    • 2
    • 3

14. Which programming construct is represented by a REPEAT UNTIL loop structure?

    • Post-condition iteration
    • Count-controlled iteration
    • Pre-condition iteration
    • Selection

15. Why might an iterative solution be preferred over a recursive solution for memory efficiency?

    • Uses less stack
    • Uses fewer registers
    • Avoids CPU usage
    • Allocates more heap

16. What name is given to the section of recursion that reduces the problem towards the base case?

    • Recursive step
    • Loop condition
    • Stack frame
    • Base case

17. A procedure alters a parameter and changes the caller's argument. How was the parameter passed?

    • By reference
    • By assignment
    • By constant
    • By value

18. Which variable lifetime lasts for the entire duration of a programme's execution?

    • Loop counter
    • Parameter
    • Local variable
    • Global variable

19. What side effect can excessive use of global variables introduce into software development?

    • Infinite looping
    • Stack overflow errors
    • Syntax compilation failure
    • Unwanted data modification

20. What is the minimum number of times a WHILE loop body will execute?

    • Infinite times
    • Zero times
    • One time
    • Two times

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