Vue Framework Practice Exam

Vue.js is a progressive JavaScript framework for building user interfaces. It is designed to be incrementally adoptable and focuses on the view layer, making it easy to integrate with other libraries or existing projects.

The Vue reactivity system automatically tracks dependencies and updates the DOM when reactive state changes. In Vue 3, it uses Proxy objects (instead of Object.defineProperty in Vue 2) to intercept get/set operations on reactive data.

Use reactive() from the Composition API:
import { reactive } from 'vue'
const state = reactive({ count: 0, name: 'Vue' })
This returns a deeply reactive proxy of the original object.

ref() wraps a single value (primitive or object) and requires .value to access it in script. reactive() wraps an object and provides direct property access.
const count = ref(0) // count.value
const state = reactive({ count: 0 }) // state.count

The Composition API is a set of function-based APIs (ref, reactive, computed, watch, lifecycle hooks) that allow organizing component logic by feature rather than by option type. It is used inside setup() or <script setup>.