Python while Loops Exercises With Answers

What does a while loop check before each iteration?

1. The indentation
2. The print output
3. The conditioncorrect
4. The loop body

Answer: The condition

Why: If the condition is true, the body runs; otherwise the loop stops.

What does the program output?

n = 2
while n < 5:
    n += 1
print(n)

1. 4
2. 2
3. 5correct
4. 6

Answer: 5

Why: n increases from 2 until it reaches 5, then the condition fails.

Which change stops this loop from running forever?

n = 1
while n < 4:
    print(n)

1. Add n += 1 inside the loopcorrect
2. Remove the colon
3. Use if instead of while
4. Change print to return

Answer: Add n += 1 inside the loop

Why: The counter must change so the condition can become false.

What does break do inside a loop?

1. Skips the current iteration
2. Restarts the loop from zero
3. Turns the condition into False
4. Exits the loop immediatelycorrect

Answer: Exits the loop immediately

Why: break transfers control to the first statement after the loop.

Complete the update so count decreases by one each time.

count = 3
while count > 0:
    print(count)
    count ____ 1

Answer: -=

Why: count -= 1 is shorthand for count = count - 1.

Complete the condition so the loop prints 1 through 4.

n = 1
while n ____ 5:
    print(n)
    n += 1

Answer: <

Why: When n reaches 5, n < 5 is false and the loop stops.

Complete the keyword that leaves the loop immediately.

while True:
    n = 1
    if n == 1:
        ____

Answer: break

Why: break ends the loop even when the condition is still true.

Complete the keyword that skips the rest of this iteration.

n = 0
while n < 3:
    n += 1
    if n == 2:
        ____
    print(n)

Answer: continue

Why: continue jumps back to the condition without running the rest of the body.

What appears on the screen?

n = 0
while n < 3:
    n += 1
print(n)

Answer: 3

Why: The loop stops when n becomes 3.

What is printed?

total = 0
n = 1
while n <= 4:
    total += n
    n += 1
print(total)

Answer: 10

Why: The loop adds 1 + 2 + 3 + 4.

What is the output?

n = 0
while True:
    n += 1
    if n == 3:
        break
print(n)

Answer: 3

Why: break runs when n reaches 3, then print shows it.

What does this code print?

n = 5
while n > 0:
    n -= 2
print(n)

Answer: -1

Why: The sequence is 3, 1, -1; the loop stops when n is no longer positive.