Vue.js Interview Questions

Vue.js is a progressive JavaScript framework for building user interfaces and single-page applications (SPAs).

Core concepts include reactive data binding, component-based architecture, directives, and lifecycle hooks.

It is designed to be incrementally adoptable and integrates with other libraries or existing projects.

Vue is used by Alibaba, Xiaomi, and GitLab for scalable, maintainable, and reactive user interfaces.

A Vue instance is the core object that powers a Vue application.

It is created using new Vue({ el: '#app', data: {}, methods: {} }) in Vue 2.x, and createApp() in Vue 3.x.

Options like data, methods, computed, watchers, and lifecycle hooks define behavior and state.

Vue instance connects the data model with the DOM, automatically updating the UI when the data changes.

It is the foundation for reactive and declarative UI development in Vue.js.

Vue Router is the official router for Vue.js, enabling navigation and dynamic route-based component rendering.

It supports nested routes, lazy loading, and history modes (hash, history, abstract).

Routes are defined in a router instance and mapped to components using and .

Router guards like beforeEach and afterEach control navigation flow and authentication.

Vue Router is essential for building multipage SPAs with route-based data fetching and lazy loading.