<template>

      <div>

          <h1>{{count}}</h1>

          <h1>{{double}}</h1>

          <button @click="increase">+1</button>

      </div>

</template>

<script lang="ts">

import { ref,computed } from ‘vue‘;    

export default {

  name: ‘App‘,

  setup(){

    const count = ref(0)

    const double = computed(()=>{

      return count.value * 2

    })

    const increase = () => {

      count.value ++

    }

    return {

      count,

      double,

      increase

    }

  } 

};

</script>