Vue · Junior · Question 41 of 75

What is `onUnmounted` used for?

✓Correct answer: Cleaning up side effects: timers, event listeners on window, subscriptions
2Fetching initial data
3Updating props before rendering

Explanation

Anything set up manually in onMounted (setInterval, addEventListener) must be torn down in onUnmounted, or it keeps running and leaks memory.

Further reading

Vue: Lifecycle Hooks ↗

Test yourself

Take the Vue · Junior quiz: questions and options are shuffled, and you get a review of your mistakes at the end.