Vue · Junior · Question 16 of 75

What is `computed()` for?

const firstName = ref("Ann");
const lastName = ref("Lee");
const fullName = computed(() => `${firstName.value} ${lastName.value}`);

✓Correct answer: A derived value that is cached and recalculated only when its reactive dependencies change
2A function that runs on every render regardless of dependencies
3A watcher that performs side effects

Explanation

A method called in the template runs on every re-render; a computed property returns the cached result until firstName or lastName changes. Computed getters should be free of side effects.

Further reading

Vue: Computed Properties ↗

Test yourself

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