Topic 2

• What is the purpose of simplifying a problem in programming?

  To represent it in an understandable way
• What is the first construct used in structured programming?

  Sequence
• How is code executed in a sequence construct?

  Line-by-line from top to bottom
• What is the purpose of branching in programming?

  To run code if a condition is met
• What is another term for branching?

  Selection
• What does iteration allow in programming?

  To execute code multiple times
• What types of loops are used in iteration?

  FOR, WHILE, REPEAT UNTIL
• What is count-controlled iteration?

  Iteration repeated a specific number of times
• How would you write a count-controlled loop in Python?

  for i in range(0,10):
• What is condition-controlled iteration?

  Iteration continues until a condition is met
• How would you write a condition-controlled loop in pseudocode?

  while i <= 20:
• What is recursion in programming?

  A subroutine calls itself during execution
• What is the stopping condition in recursion?

  The condition at which recursion stops
• How does recursion compare to iteration?

  Produces the same result but is different
• What is an advantage of using recursion?

  Fewer lines of code, less prone to errors
• Why is it essential to define recursive subroutines clearly?

  To reach a stopping condition after finite calls
• What is a common example of a recursive function?

  Factorial function
• What happens each time a recursive function calls itself?

  A new stack frame is created
• What is stored in a stack frame?

  Parameters, local variables, return addresses
• What does it mean for a subroutine to unwind?

  Information is popped off the call stack
• What is a disadvantage of recursion?

  Inefficient use of memory
• What is a stack overflow?

  When the call stack runs out of memory
• What is tail recursion?

  A more efficient form of recursion
• Why is recursion difficult to trace?

  Due to multiple function calls
• What does scope refer to in programming?

  The section of code where a variable is available
• What are local variables?

  Variables accessible only within their block
• Why are local variables considered good practice?

  They ensure subroutines are self-contained
• What are global variables?

  Variables accessible across the whole program
• What is a disadvantage of global variables?

  They can be unintentionally overwritten
• What happens if a local variable has the same name as a global variable?

  The local variable takes precedence
• What is modular programming?

  A technique to split programs into modules
• What is the benefit of modular design?

  Makes problems easier to understand and manage
• What is the top-down approach in programming?

  Breaking down problems into sub-problems
• What is stepwise refinement?

  Breaking down problems into smaller tasks
• What are subroutines?

  Named blocks of code performing specific tasks
• What is the difference between procedures and functions?

  Functions must return a value, procedures do not
• How can procedures return values?

  They can return multiple values
• What is an example of a function?

  Function isEven(number) returns True or False
• What happens when parameters are passed by value?

  A copy of the value is passed
• What does passing by reference mean?

  The address of the parameter is given