Vue JS 3 Tutorial 09 Dạo quanh Composition API trong Vue (ok)

C:\Users\Administrator\Desktop\vue3\src\views\AboutView.vue

<template>
  <div class="about">
    <h1>This is an about page 1 {{ FirstName }}</h1>
    <h2>This is an about page 2 {{ car.name }}</h2>
    <h3>This is an about page 3 {{ car.price }}</h3>
    <h4>This is an about page 4 {{ obj.key }}</h4>
    <button @click="changFirstName">changFirstName</button>
  </div>
</template>
<script>
import { reactive, ref } from "vue";
export default {
  setup() {
    let FirstName = ref("First");
    let car = reactive({
      name: "Car",
      price: 5000
    });
    let obj = ref({
      'key' : 'Test object'
    })
    function changFirstName() {
      car.name = "Car Test";
      obj._value.key = "GGGGGGGG 🤣";
      this.FirstName = "Abc";
    }
    return {
      FirstName,
      car,
      obj,
      changFirstName
    }
  }
}
</script>