Vue JS Study Guide 2026
Everything you need to pass the Vue JS exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 Vue JS Exam Format at a Glance
📚 Vue JS Topics to Study (51)
✍️ Sample Vue JS Questions & Answers
1. Which composable utility converts all properties of a reactive object into individual refs?
toRefs() destructures a reactive object into individual refs while maintaining the reactive connection for each property.
2. What is the purpose of the key attribute in a v-for loop?
The key helps Vue's virtual DOM efficiently track and reuse elements when the list changes.
3. Which lifecycle hook should you use to fetch initial data when a component loads?
Data fetching is typically done in `onMounted`. If the fetch doesn't need DOM access, you can also start it in `setup()` directly, which runs slightly earlier.
4. What does let you do?
moves rendered content to a target location outside the parent's DOM tree.
5. How do you implement async validation (e.g., checking if a username is taken) in Vue 3?
Async validation uses a watcher on the field value, debounced to avoid excessive API calls. The result updates an error ref that's displayed conditionally.
6. What is the function of with async components?
displays a fallback slot until nested async dependencies finish loading.