What is Vue - Practice Questions & Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is Vue's primary purpose?

Vue is a popular tool in web development. What is its main job?

A To style web pages with colors and fonts

B To manage databases and server-side logic

C To build user interfaces and single-page applications

D To write backend APIs in Node.js

💡 Hint

Think about what you see and interact with on websites.

Vue is a JavaScript framework mainly used to create interactive user interfaces and single-page applications.

❓ component_behavior

intermediate

What happens when you update a reactive property in Vue?

In Vue, if you change a reactive data property, what does Vue do?

A It ignores the change until the user refreshes the page

B It reloads the entire webpage

C It sends the data to the server immediately

D It automatically updates the parts of the webpage that use that data

💡 Hint

Vue tracks data changes to keep the page in sync.

Vue uses a reactive system that detects data changes and updates the webpage automatically without reloading.

📝 Syntax

advanced

Which Vue 3 syntax correctly defines a reactive state using Composition API?

Choose the correct way to create a reactive count variable in Vue 3 Composition API.

A const count = ref(0);

B const count = reactive(0);

C const count = reactive({ value: 0 });

D const count = ref({ count: 0 });

💡 Hint

Use ref for primitive values like numbers.

In Vue 3, ref is used to create reactive primitive values, while reactive is for objects.

🔧 Debug

advanced

Why does this Vue component not update the displayed count?

Look at this Vue 3 component code snippet: Why does clicking the button not change the number shown?

A Because the template syntax {{ count }} is incorrect

B Because count is a plain variable, not reactive, so Vue does not track changes

C Because the increment function is not called on button click

D Because the script setup block is missing the export default statement

💡 Hint

Vue needs reactive variables to update the UI automatically.

Declaring count as a plain variable means Vue does not track its changes, so the UI stays the same.

❓ lifecycle

expert

When does the Vue 'onMounted' lifecycle hook run?

In Vue 3, the 'onMounted' hook is used inside setup(). When exactly does it run?

A After the component is added to the DOM and rendered

B Immediately when the script setup block starts running

C When the component is destroyed and removed from the DOM

D Before the component is created but after props are set

💡 Hint

Think about when you want to run code that needs the component visible on the page.

'onMounted' runs after the component is fully rendered and attached to the page, perfect for DOM-dependent code.