Top 10 Vue3 Interview Questions: Practice Questions with Answers and Code Examples

This article lists 10 Vue3 interview questions, each question contains answers and code examples, I hope it will be helpful for your interview.

1. What is Vue3?

Vue3 is the next major version of Vue.js, and it brings a lot of important improvements and new features, including faster rendering, better type support, better composition API, and more.

1. What is Composition API?

The Composition API is a new feature in Vue3 that allows developers to organize code in terms of functions rather than options, making the code easier to understand and maintain.

1. How to create a component in Vue3?

Creating a component in Vue3 is very simple, just use the defineComponent function to define a component, and write the template and logic in it.

import {
    
     defineComponent } from 'vue'

export default defineComponent({
    
    
  name: 'MyComponent',
  template: `
    <div>
      <h1>Hello, {
     
     { name }}!</h1>
    </div>
  `,
  props: {
    
    
    name: String
  }
})

1. How to define and use responsive data in Vue3?

In Vue3, reactive data can be defined and used using ref and reactive functions. The ref function is used to define a single reactive data, and the reactive function is used to define an object containing multiple reactive data.

import {
    
     ref, reactive } from 'vue'

const count = ref(0)
const user = reactive({
    
    
  name: 'Alice',
  age: 18
})

1. How to use composition API in Vue3?

In Vue3, you can use the setup function to use the composition API. The setup function must return an object, which can contain reactive data, computed properties, methods, etc.

import {
    
     defineComponent, ref } from 'vue'

export default defineComponent({
    
    
  setup() {
    
    
    const count = ref(0)

    const increment = () => {
    
    
      count.value++
    }

    return {
    
    
      count,
      increment
    }
  }
})

1. How to create a custom directive in Vue3?

In Vue3, a custom directive can be created using the directive function. The directive function needs to pass in two parameters, the first parameter is the instruction name, and the second parameter is the instruction object, which contains lifecycle functions such as bind, update, and unbind.

import {
    
     directive } from 'vue'

const myDirective = directive('my-directive', {
    
    
  mounted(el, binding) {
    
    
    // 在元素挂载时调用
  },
  updated(el, binding) {
    
    
    // 在元素更新时调用
  },
  unmounted(el, binding) {
    
    
    // 在元素卸载时调用
  }
})

export default myDirective

1. How to use Teleport component in Vue3?

In Vue3, you can use the Teleport component to render the output of the component into a specified DOM node. The Teleport component needs to pass in a target attribute, specifying the DOM node to be rendered to.

import {
    
     defineComponent } from 'vue'

export default defineComponent({
    
    
  template: `
    <teleport to="#modal">
      <div>
        <!-- 这里是弹窗的内容 -->
      </div>
    </teleport>
  `
})

1. How to use Suspense components in Vue3?

In Vue3, you can use the Suspense component to display placeholder content before the asynchronous component loads. The Suspense component needs to pass in a fallback attribute to specify the placeholder content to be displayed.

import {
    
     defineAsyncComponent } from 'vue'

const AsyncComponent = defineAsyncComponent(() =>
  import('./AsyncComponent.vue')
)

export default {
    
    
  template: `
    <suspense>
      <template #default>
        <AsyncComponent />
      </template>
      <template #fallback>
        <div>Loading...</div>
      </template>
    </suspense>
  `
}

1. How to use Provide/Inject in Vue3?

In Vue3, you can use the provide function to provide data, and then use the inject function to inject data in the child component. Provide and inject can easily realize data sharing between cross-level components.

import {
    
     provide, inject } from 'vue'

const MyComponent = {
    
    
  setup() {
    
    
    const foo = 'bar'
    provide('foo', foo)
  }
}

const MyChildComponent = {
    
    
  setup() {
    
    
    const foo = inject('foo')
    return {
    
     foo }
  }
}

1. How to use global API in Vue3?

In Vue3, you can use the createApp function to create an application instance, and use the global API to register components, directives, plugins, etc.

import {
    
     createApp } from 'vue'
import MyComponent from './MyComponent.vue'
import MyDirective from './MyDirective.js'
import MyPlugin from './MyPlugin.js'

const app = createApp()
app.component('my-component', MyComponent)
app.directive('my-directive', MyDirective)
app.use(MyPlugin)
app.mount('#app')

The above are the first 10 Vue3 interview questions in this article, I hope it will be helpful to you. If you want to know more about Vue3, please continue reading the rest of this article.