Vue3 面试题, Vue3
Vue3 面试题, Vue3
QA
Step 1
Q:: What is Vue 3 and how does it differ from Vue 2?
A:: Vue 3 is the latest major version of the Vue.js framework. It introduces a new composition API that allows for better logic composition and code reuse. Additionally, Vue 3 offers improved performance, better TypeScript support, and a smaller bundle size compared to Vue 2.
Step 2
Q:: Explain the Composition API in Vue 3.
A:: The Composition API is a set of additive, function-based APIs that allow developers to better organize and reuse code. It is introduced in Vue 3 as an alternative to the Options API. With the Composition API, you can encapsulate logic into reusable functions and more easily share stateful logic across components.
Step 3
Q:: What are reactive refs in Vue 3 and how are they used?
A:: Reactive refs are a new feature in Vue 3 that allows developers to create reactive references to data. Using the ref function from the Composition API, you can create a reactive reference to a value, which will automatically update the view when the value changes. For example, const count = ref(0); creates a reactive reference to a count variable.
Step 4
Q:: Describe the setup() function in Vue 3.
A:: The setup() function is a new lifecycle hook in Vue 3 that serves as the entry point for using the Composition API. It is executed before the component is created, and it can be used to define reactive state, computed properties, and methods. The setup() function returns an object that is made available to the template.
Step 5
Q:: What are the benefits of using the Teleport component in Vue 3?
A:: The Teleport component in Vue 3 allows you to render a component or part of a component outside of its parent element, typically to the root of the DOM or to a different location in the DOM tree. This is particularly useful for rendering modals, tooltips, or any other UI elements that need to break out of their parent container's styling or layout constraints.
Step 6
Q:: How do you use the new Fragment feature in Vue 3?
A:: Fragments in Vue 3 allow a component to return multiple root nodes, rather than just one. This is useful for reducing unnecessary wrapper elements in the DOM. You can use fragments by simply returning an array of nodes in the render function or the template.
Step 7
Q:: Explain the purpose of the provide and inject APIs in Vue 3.
A:: The provide and inject APIs allow for dependency injection in Vue 3, enabling a component to provide data or methods that can be accessed by any of its descendants in the component tree. This is useful for passing down state or functions without prop drilling.
Step 8
Q:: What is the new reactivity system in Vue 3 and how does it work?
A:: Vue 3 introduces a proxy-based reactivity system that is more efficient and flexible than the object.defineProperty-based system used in Vue 2. This new system uses ES6 Proxies to observe changes to objects and arrays, allowing for better performance and support for more complex data structures.
用途
These topics are crucial for a Vue`.js developer to understand as they cover the core features and enhancements of Vue 3, which are essential for building efficient and scalable web applications. Knowing these concepts ensures that developers can leverage the full power of Vue 3 in their projects, improving code maintainability, performance, and developer productivity.`\n相关问题
Vue 进阶面试题, Vue3
QA
Step 1
Q:: 什么是 Vue3 的 Composition API?
A:: Vue3 的 Composition API 是一种组织代码的新方式，它允许开发者将逻辑从组件中提取出来，并在多个组件之间共享。它通过函数的形式来组合逻辑，使代码更加模块化和可复用。相比 Vue2 的 Options API，Composition API 提供了更大的灵活性，尤其是在处理复杂组件逻辑时。
Step 2
Q:: Vue3 中的 ref 和 reactive 有什么区别?
A:: ref 用于定义一个响应式的数据值，可以是基本类型或对象，而 reactive 则用于将一个对象全部转换为响应式对象。ref 在需要在模板中解构时需要使用 .value，而 reactive 是直接使用对象本身。
Step 3
Q:: 如何在 Vue3 中使用 watch 和 watchEffect``?
A:: watch 用于监听特定数据源的变化并执行副作用逻辑，而 watchEffect 则会自动追踪内部依赖的变化并执行副作用。watch 适合明确依赖的数据源，而 watchEffect 更适合需要立即执行并自动追踪依赖的场景。
Step 4
Q:: Vue3 的 Teleport 是什么？它的应用场景是什么？
A:: Teleport 是 Vue3 中的一个新特性，它允许你将组件的 DOM 结构渲染到应用的 DOM 结构之外的任意位置。这在处理如模态框、通知等需要脱离组件树渲染的元素时非常有用，可以更好地组织代码结构和管理 DOM 层次。
Step 5
Q:: Vue3 中的 provide/inject 和 props、emit 机制有什么区别？
A:: provide/inject 是一种在组件树的祖先与后代组件之间共享数据的方法，而不必通过 props 层层传递或 emit 事件。这适合共享全局状态或配置。而 props 和 emit 则是用于父子组件之间传递数据的常规机制，适合在层级关系明确时使用。