Programming Basics: Make a While Loop Stop

Check a condition before each repetition and track progress toward stopping.

All worksheets

5 questions0m 0s

Learn the skill

WHILE checks its condition before each iteration. Trace SET count TO 0; WHILE count < 3: SET count TO count + 1; END; SHOW count. Use integer values and update your trace after each body execution.

Worked example

The condition is true at count 0, 1 and 2. Each pass adds 1. At count 3 the condition is false, so the loop stops and SHOW displays 3.

Starting at count zero, the condition count less than three is true for entry values zero, one and two. Each iteration adds one. At count three the condition is false and the loop exits.

Would you believe it?

A loop can execute its body zero times. Skipping the body does not skip the whole program: later instructions can still run.

Python documentation: loops

Question 1 What is count after the first body execution? 1 0 3

Question 2 How many times does the example execute its body? 4 2 3

Question 3 What does the final SHOW display? 4 3 2

Question 4 If count starts at 3 instead, how many body executions occur? 0 1 3

Question 5 If the update is removed while count starts at 0, what happens in this model? It still stops after 3 passes It stops immediately The loop never reaches a false condition

Review your work

0correct

Complete the questions to review each answer.

View dashboard