The difference between Vue3 and Vue2: a simpler API

The difference between Vue3 and Vue2: simpler API

Vue.js is a popular front-end framework that is widely used to build single-page applications and interactive user interfaces. With the release of Vue 3, we will see some exciting new features and improvements, the most notable of which is a cleaner API. In this article, we will explore the differences between Vue3 and Vue2 and illustrate these differences using some code examples.

1. Composition API

Vue3 introduces a new way called Composition API to write component logic. This API is based on the idea of ​​functional programming, which allows us to organize code according to logical fragments (such as calculated properties, life cycle hooks, etc.). Compared with the Options API in Vue2, the Composition API is more flexible and reusable. Here is a simple example to demonstrate the differences:

Options API example in Vue2:

<template>
  <div>
    <h2>{{ message }}</h2>
    <button @click="increaseCounter">Increase</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      message: 'Hello Vue!',
      counter: 0
    }
  },
  methods: {
    increaseCounter() {
      this.counter++
    }
  }
}
</script>

Composition API example in Vue3:

<template>
  <div>
    <h2>{{ message }}</h2>
    <button @click="increaseCounter">Increase</button>
  </div>
</template>

<script>
import { ref } from 'vue'

export default {
  setup() {
    const message = ref('Hello Vue!')
    const counter = ref(0)

    function increaseCounter() {
      counter.value++
    }

    return {
      message,
      counter,
      increaseCounter
    }
  }
}
</script>

From the above example It can be seen that the Composition API in Vue3 is clearer and concise. We can use ref functions to create responsive data and use ordinary JavaScript functions to manage component logic.

2. Static type checking

Vue3 uses TypeScript to enhance the type checking function, which allows us to find more errors during compilation. Compared with template static type checking in Vue2, Vue3's type checking is more comprehensive and reliable. Here is a simple example to demonstrate the differences:

Template static type checking example in Vue2:

<template>
  <div>
    <h2>{{ message }}</h2>
    <button @click="increaseCounter">Increase</button>
  </div>
</template>

<script>
export default {
  data() {
    return {
      message: 'Hello Vue!',
      counter: 0
    }
  },
  methods: {
    increaseCounter() {
      this.counter++
    }
  }
}
</script>

TypeScript type checking example in Vue3:

<template>
  <div>
    <h2>{{ message }}</h2>
    <button @click="increaseCounter">Increase</button>
  </div>
</template>

<script lang="ts">
import { ref } from 'vue'

interface ComponentData {
  message: string
  counter: number
}

export default {
  setup() {
    const data: ComponentData = {
      message: 'Hello Vue!',
      counter: 0
    }

    function increaseCounter() {
      data.counter++
    }

    return {
      message: ref(data.message),
      counter: ref(data.counter),
      increaseCounter
    }
  }
}
</script>

in Vue3 , we can write more robust code by explicitly declaring the type of component data using TypeScript's interface.

3. Better performance

Vue3 has made some major optimizations in terms of performance. By using Proxy objects and incremental update algorithms, Vue3 implements a more efficient reactive system. This makes Vue3 perform better in large applications and have a lower memory footprint. In addition, Vue3 also introduces a new compiler, providing better code optimization and tree shaking optimization to further improve performance.

Conclusion

Vue3 brings some exciting changes, the most obvious of which is a cleaner API. The Composition API makes component logic more readable and maintainable, while TypeScript support provides more reliable static type checking. In addition, Vue3 also brings better performance, making it a better choice for building modern web applications.

While migrating to Vue3 may take some time and effort, considering the many benefits it brings, I believe it will be a process worth investing in. Let us look forward to the official release of Vue3 and more exciting features and improvements!

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