Vue · Junior · Question 61 of 75

Why does `v-for` need a unique `:key`?

✓Correct answer: So Vue can track each item's identity and reuse or move the right DOM nodes and component state
2Keys make the list sorted
3Without a key the list doesn't render

Explanation

Use a stable id from the data. Without keys, Vue patches in place, which can mix up inputs or component state when the order changes.

Further reading

Vue: List Rendering ↗

Test yourself

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