Lecture 8 - Exercises

8A - For Loops

1. What does the following program print?

   m = 0
   for n in [1.8, 4.2, 1.6, 2.0, 1.88]:
     m += int(n)
   print(m)

2. What is the output of the following program?

   s = ""
   i = 1
   for digit in ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]:
     if len(digit) < 5 and i % 2 == 1:
        s = digit + s
     i += 1
   print(s)

8B - The range function

What does each of the following range calls, converted to a list, evaluate to?

3. list(range(3))
4. list(range(4, 7))
5. list(range(4, 0, -1))

How many elements are in the following ranges?

6. range(732)

7. range(6, 88)

8. range(4, 2)

9. range(20, 21)

10. range(0)

11. What does the following program print?

for x in range(1,4):
   print(x + x * x, end=str(x))

Consider the following incomplete program:

x = 
y = 
for z in range(x, y):
  print("WWU")

12. What pairs of values could be assigned to the variables x and y so that the program prints WWU 43 times? Select all correct choices.

    1. x: 0 y: 44
    2. x: -21 y: 22
    3. x: -21 y:21
    4. x: -789 y: -746
    5. x: -789 y: 746
    6. x: 1 y: 44

13. Write a program that prompts the user for a positive integer \(p\) and uses a for loop to print the powers of 2 up to \(2^p\) (starting at \(p\) == 0).