<template>
  <div>
    <el-input-number v-model="state.one" :min=1></el-input-number>
    <el-input-number v-model="state.two" :min=2></el-input-number>
    <el-input disabled  style="width:50px" v-model="state.total"></el-input>
  </div>
</template>
<script setup lang='ts'>
  import {reactive,computed} from 'vue'
 
  let state=reactive({
    one:0,
    two:0,
    total:0
  })
  //computed必须返回值
  state.total=computed(()=>{
    return state.one+state.two 
  }) as any
</script>
<style scoped>
</style>

computed与watch监听的区别，computed必须有返回值(return)