While loops in MATLAB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a while loop in MATLAB?

A while loop in MATLAB repeats a block of code as long as a given condition is true. It checks the condition before each repetition.

beginner

How do you write a basic while loop in MATLAB?

Use the syntax:<br>

while condition
    % code to repeat
end

<br>The loop runs while 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 because the condition is checked before the first iteration.

intermediate

How can you avoid an infinite while loop in MATLAB?

Make sure the condition will eventually become false by changing variables inside the loop. Otherwise, the loop runs forever.

beginner

Example: What does this MATLAB code print?<br>

i = 1;
while i <= 3
    disp(i)
    i = i + 1;
end

It prints:<br>1<br>2<br>3<br>Because the loop runs while i is 1, 2, and 3, then stops when i becomes 4.

What does the while loop check before each repetition?

A The number of times it has run

B The condition to decide if it should run

C The last value printed

D The size of the array

A while loop checks the condition before each repetition to decide if it should continue running.

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

A The loop stops immediately

B The program crashes

C The loop runs forever (infinite loop)

D The loop runs once

If the condition never becomes false, the while loop runs forever, causing an infinite loop.

Which keyword ends a while loop in MATLAB?

A end

B stop

C finish

D close

In MATLAB, the keyword 'end' is used to close a while loop block.

What will this code print?<br>i = 5;<br>while i < 3<br>disp(i)<br>i = i + 1;<br>end

A 1, 2

B 3, 4, 5

C 5

D Nothing

Since the condition i < 3 is false at the start (i=5), the loop does not run and prints nothing.

How can you make sure a while loop eventually stops?

A Change the condition variable inside the loop

B Use a for loop instead

C Add a break statement outside the loop

D Do not change any variables

To avoid infinite loops, you must change the variable in the condition inside the loop so it eventually becomes false.

Explain how a while loop works in MATLAB and give a simple example.

Think about how you repeat a task until something changes.

Describe how to prevent an infinite loop when using while loops.

What must happen inside the loop to stop it?