While loop execution flow in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the basic structure of a while loop in Python?

A while loop starts with the keyword while, followed by a condition and a colon. The code inside the loop is indented and runs repeatedly as long as the condition is true.

beginner

What happens if the condition in a while loop is initially false?

The code inside the while loop does not run at all, and the program continues with the code after the loop.

beginner

How does the while loop decide when to stop?

The while loop checks the condition before each iteration. If the condition becomes false, the loop stops running.

intermediate

What can cause an infinite loop in a while loop?

If the condition never becomes false because the code inside the loop does not change the variables involved, the loop will run forever, causing an infinite loop.

intermediate

How can you safely exit a while loop before the condition becomes false?

You can use the break statement inside the loop to stop it immediately, regardless of the condition.

What does the while loop check before running its code block?

A The loop condition

B The number of times it has run

C The last value printed

D The function return value

The while loop checks the condition before each iteration to decide if it should run the code inside.

What happens if the while loop condition is false at the start?

A The loop runs once

B The loop does not run at all

C The loop runs infinitely

D The loop runs twice

If the condition is false at the start, the while loop skips the code inside and continues after the loop.

Which statement can stop a while loop immediately?

A continue

B pass

C return

D break

The break statement stops the loop immediately, exiting it regardless of the condition.

What is a common cause of an infinite while loop?

A Using a break statement

B Changing the loop variable inside the loop

C Not changing the loop condition inside the loop

D Using an else clause

If the loop condition never changes to false, the loop will run forever, causing an infinite loop.

When does the while loop check its condition?

A Before running the loop code

B After running the loop code

C Only once at the start

D Only if a break is used

The while loop checks the condition before each iteration to decide whether to run the loop code.

Explain how a while loop executes step-by-step.

Think about what happens before and after the loop code runs.

Describe what can cause an infinite loop and how to prevent it.

Focus on the condition and how it changes.