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Year 9 Computing — Procedures, and calling them

Read a program that gives a block of lines a name, and say what runs, when, and how many times.

Name: ________________________

  1. 1.One of these four lines never runs at all. Which one?

    def alpha():
    print(1)

def beta():
    print(2)

alpha()
print(3)
    • a) The line printing 2
    • b) The line printing 3
    • c) The line printing 1
    • d) The line calling alpha

  2. 2.A procedure whose body is a single printing line is used in five different programs. Match each way of using it to how many times its body runs.

    • Defined but never called
    • Called once at the end of the program
    • Called inside a loop over range(1, 6)
    • Called twice, and again inside a loop over range(1, 5)
    • Called inside a loop over range(1, 3) that itself sits inside a loop over range(1, 5)
    • 1
    • 8
    • 6
    • 5
    • 0

  3. 3.A loop does the calling here. How many numbers does it print?

    def pair():
    print(1)
    print(2)

for n in range(1, 4):
    pair()

  4. 4.Follow this code by hand. How many times does the line printing 3 run?

    def step():
    print(3)

for n in range(1, 5):
    step()

  5. 5.Follow this code by hand. What is the first number it prints?

    def mark():
    print(10)

def note():
    print(20)

note()
mark()

  6. 6.The named block has a loop inside it. How many numbers does it print?

    def show():
    for n in range(1, 4):
        print(n)

show()
show()

  7. 7.Read this program from the top down. How many numbers does it print?

    def show():
    print(5)
    • a) 0
    • b) It cannot be run at all
    • c) 1
    • d) 5

  8. 8.A loop calls a block that calls another block. How many numbers does it print?

    def inner():
    print(1)

def outer():
    inner()
    inner()

for n in range(1, 5):
    outer()

Answer key — Year 9 Computing — Procedures, and calling them

  1. 1. a) The line printing 2
  2. 2. Defined but never called → 0; Called once at the end of the program → 1; Called inside a loop over range(1, 6) → 5; Called twice, and again inside a loop over range(1, 5) → 6; Called inside a loop over range(1, 3) that itself sits inside a loop over range(1, 5) → 8
  3. 3. 6
  4. 4. 4
  5. 5. 20
  6. 6. 6
  7. 7. a) 0
  8. 8. 8