ChallengesLog in Sign up

Free debugging practice for CS students. Fix real bugs, learn the patterns behind them.

Practice

All challenges
Python challenges
JavaScript challenges
Beginner friendly

Bug patterns

Off-by-one errors
Infinite loops
Null and undefined errors
Type errors
All bug patterns

Account

Create an account
Log in

About Privacy Terms Contact

© 2026 BugHunt

Your code runs in your browser, never on our servers.

isEven that returns the opposite — JavaScript debugging challenge | BugHunt

javascriptLogic errorEasy

isEven that returns the opposite

Time: 0:00

What it should do

isEven(n) should return true if n is even, false otherwise.

What goes wrong

isEven(4) returns false and isEven(3) returns true — the results are backwards.

Log in to save your progress.

Hints

This is a logic errors bug

The wrong operator, an inverted condition, a formula the right way round but backwards.

Learn the logic errors pattern