While loop in Swift - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a while loop in Swift?

A while loop repeats a block of code as long as a condition is true. It checks the condition before running the code each time.

intermediate

How does a while loop differ from a repeat-while loop in Swift?

A while loop checks the condition before running the code, so it might not run at all. A repeat-while loop runs the code first, then checks the condition, so it runs at least once.

beginner

Write a simple Swift while loop that counts from 1 to 5.

var count = 1 while count <= 5 { print(count) count += 1 }

beginner

What happens if the condition in a while loop never becomes false?

The loop runs forever, causing an infinite loop. This can freeze or crash your program.

beginner

Why is it important to update variables inside a while loop?

Updating variables changes the condition so the loop can eventually stop. Without updates, the loop might run forever.

What does a while loop do in Swift?

A Stops the program immediately

B Runs code only once

C Runs code after checking the condition once

D Repeats code while a condition is true

A while loop repeats the code block as long as the condition remains true.

When does a while loop check its condition?

A Only once at the start

B After running the loop code

C Before running the loop code

D It never checks

The while loop checks the condition before each iteration.

What will happen if the condition in a while loop is always true?

A The loop runs forever (infinite loop)

B The loop runs once

C The loop never runs

D The program crashes immediately

If the condition never becomes false, the loop never stops.

Which of these is a correct way to stop a while loop?

A Change the condition variable inside the loop

B Do nothing

C Use a for loop instead

D Write code outside the loop

Updating the variable that controls the condition lets the loop end.

What is the output of this code? var i = 3 while i > 0 { print(i) i -= 1 }

A 1 2 3

B 3 2 1

C 0 1 2

D No output

The loop prints 3, then 2, then 1, then stops when i becomes 0.

Explain how a while loop works in Swift and why updating the condition variable inside the loop is important.

Think about what happens if the condition never changes.

Write a simple Swift while loop that prints numbers from 1 to 5 and explain each step.

Start with a variable set to 1 and increase it each time.