10 Best Vue Interview Questions in 2023
Looking to hire your next Vue developer? Then, you need the best Vue interview questions. Here are the 10 top questions to ask your candidates.
Vue interviews
Vue.js, or Vue, is an open-source front-end JavaScript framework used for building single-page applications and user interfaces. It was originally created in 2014 by Evan You to be a lightweight framework based on the parts of AngularJS that You enjoyed working with.
Vue focuses on declarative rendering and component composition, with an adaptable architecture. Advanced features are offered via officially maintained supporting libraries and packages.
But if you're hiring for an open role, how do you choose among your Vue candidates? Here are some of the top Vue interview questions.
Beginner Vue interview questions
First and foremost, what are some good Vue interview questions to ask junior developers? These are basic questions that you can ask younger developers who may not be that familiar with Vue just yet.
1. What is Vue?
Answer:
Vue is a progressive, open-source JavaScript framework that is used to build single-page applications and user interfaces that are incrementally adoptable. It’s easy to integrate with other libraries. Vue is also easy to learn and doesn’t require you to install anything else other than a Vue.js library.
2. What are the advantages of Vue?
Answer:
Vue has plenty of advantages, such as:
It’s easy to understand and, therefore, it’s easy to add to a project.
The framework is small in size and it takes no time for the user to download or use it. The framework is 18-21kB in size.
Vue is easy to integrate with existing applications.
It’s a flexible framework and if developers know Angular.js, React.js, or any other JavaScript framework, they are likely to understand Vue.
Vue uses a virtual DOM -- a lightweight, in-memory tree representation of the original HTML DOM that is updated without affecting the original DOM. This is similar to other frameworks, such as Ember and React.js.
It uses components, which are used to create reusable custom elements in Vue applications.
Vue facilitates two-way communication as its MVVM architecture makes it easy to handle HTML blocks.
3. What are the major features of Vue?
Answer:
The different features of Vue are:
Virtual DOM: Virtual DOM is a lightweight in-memory tree representation of the original HTML DOM. It’s updated without affecting the original DOM.
Templates: Vue includes HTML-based templates that bind the DOM with the Vue instance data.
Routing: Navigation between pages is achieved through routing.
Components: Components are used to create reusable custom elements in Vue applications.
Documentation: Vue includes easy documentation.
Great tools: The framework has great tools, such as CLI, that can create your initial application setup.
Advanced Vue interview questions
What are some advanced Vue interview questions? Here are a few technical questions to help you assess your candidates.
4. What is a single-file component?
Answer:
This is a file with a .vue extension. It's a special file format that lets you include the template, styling, and logic of a Vue component in a single file.
To set up a single-file component, you need to set up Vue Loader for parsing the file. This is typically done as part of a web pack building pipeline.
5. What are Vue Mixins?
Answer:
Mixins offer a flexible way to reuse functionalities or code to instances and components. They are written in a separate file where they can be shared across different components many times over. Global Mixins are another option; however, they can affect every Vue instance that is created afterward.
6. How does data flow work between components in a Vue application?
Answer:
Vue uses a one-way data flow. Using a prop or a custom attribute, data passes to child components from a parent component. This prop/custom attribute then becomes a property on the child component instance.
The prop value is automatically updated in the child component when it’s updated in the parent component; it should not be separately mutated in the child component.
Via an event, the child component can communicate back to the parent. And the parent can assign a handler to an event so that data can be passed back to the parent.
7. What is the difference between slots and scoped slots?
Answer:
A slot is a placeholder in a child component. It’s filled with content passed from the parent. A slot is first compiled in the parent’s scope and it’s then passed to the parent.
You can’t use child component properties in a slot’s content; however, scoped slots let you pass data from the child component to the parent scope. That data can then be used in slot content.
8. Explain Reactivity in Vue.
Answer:
When you change data value, a page update is triggered to reflect data changes. Vue data property is reactive.
9. What does the Vue lifecycle look like?
Answer:
Vue instances pass through functions that are called lifecycle hooks. There are eight lifecycle hooks for every Vue instance:
Before create: After a Vue instance has been initialized, this lifecycle hook is called.
Created: When the Vue instance has set initial properties, data, and so on, this hook is called just after the “Before create” hook.
Before mount: This hook is called when the template has been compiled and just before the instance is mounted on DOM.
Mounted: Once the template is ready with data and functional, this hook is called.
Updated: The hook is called just after DOM has updated.
Before destroy: A place where you can perform resource clean-up before you destroy the Vue instance.
Destroyed: When all Vue instances have been destroyed, this hook gets called. It’s triggered when the destroy method is run on an object in code.
10. How do you use $parent?
Answer:
You use $parent to access the parent component instance in the child component. The application becomes harder to test and debug. You can also use $child for a child component instance.
Over to you!
There you have it! Now you know what the 10 most important Vue interview questions are.
The thing to look out for in your interviews is technical knowledge, but not just that. Use your interviews primarily to assess how well candidates communicate their knowledge, rather than getting a clear understanding of their skills.
You see, skills are better assessed with skills assessment tests.
If you want to combine your Vue interviews with skill assessment tools, try CodeSubmit today.