Python Control Flow: Loops Questions and Answers

Question 1

What is the final value of `total` after this `while` loop finishes?

Accepted Answer

10

Answer

The loop executes for `count` values of 0, 1, 2, 3, and 4. The `total` accumulates the sum of these numbers: 0 + 1 + 2 + 3 + 4 = 10. When `count` becomes 5, the condition `5 < 5` is false, and the loop terminates.

Question 2

In Python, under which circumstance is the `else` block of a `for` loop executed?

Accepted Answer

It is only executed if the loop completes all its iterations without being terminated by a `break` statement.

Answer

The `else` clause for a loop runs only when the loop has completed its iterations normally. If the loop is exited prematurely with a `break` statement, the `else` block is skipped. It is a way to run code when a `break` was not encountered.

Question 3

A developer wants to sum only the odd numbers from a list. What will the following code print?

Accepted Answer

9

Answer

The `continue` statement skips the remainder of the current iteration and proceeds to the next. When `num` is even (2 and 4), the `continue` statement is executed, and the line `total += num` is skipped. Therefore, only the odd numbers (1, 3, 5) are added to `total`, resulting in 1 + 3 + 5 = 9.

Question 4

What is the final value of `count` after the following nested loops complete execution?

Accepted Answer

6

Answer

This is a nested loop. The outer loop runs 3 times (for i = 0, 1, 2). For each iteration of the outer loop, the inner loop runs completely, which is 2 times (for j = 0, 1). Therefore, the innermost statement `count += 1` is executed a total of 3 * 2 = 6 times.

Question 5

What will be the output of the following Python code snippet that uses a `break` statement?

Accepted Answer

10

Answer

The `for` loop iterates through the numbers generated by `range(10)`. The `break` statement causes the immediate termination of the loop when `i` becomes 5. Consequently, the loop only processes the values of `i` from 0 up to 4. The sum accumulated in `result` is 0 + 1 + 2 + 3 + 4, which equals 10.

Python Practice Test

Python Practice Test

Python Control Flow: Loops Questions and Answers