对象追加属性 删除属性 判断空对象

Object.assign({}, this.$route.params, {pageNo: val})

var obj= {
  height: 180,
  long: 180,
  weight: 180,
  hobby: {
    ball: 'good',
    music: 'nice'
  }
}
delete obj.hobby

JSON.stringify(back) !== '{}'