of 循环 改变 对象值 对const的理解 对象的字面量 计算属性

const arr = [{a:23,b:34},{a:123,b:134}]
console.log(arr)
for (let v of arr){
console.log(v)
const old = v.a
v.a=old*old
console.log(v)
}
console.log(arr)

arr已经发生了改变

场景

微信小程序开发

对后端接口的时间戳格式数据处理

mpBMCwepysrcutilsutil.js


const timestampSecondsToTime = (tmp) => {
  const t = function (i) {
    return (i < 10 ? '0' + (i) : i)
  }
  const date = new Date(tmp * 1000)
  const Y = date.getFullYear() + '-'
  const M = t(date.getMonth() + 1) + '-'
  const D = t(date.getDate()) + ' '
  const h = t(date.getHours()) + ':'
  const m = t(date.getMinutes()) + ':'
  const s = t(date.getSeconds())
  return Y + M + D + h + m + s
}
const convertArrObjListTimestamp = (arr, timestampKey) => {
  for (let v of arr) {
    const old = v[timestampKey]
    v[timestampKey] = timestampSecondsToTime(old)
  }
  return arr
}
export default {
  isInClosedInterval,
  isLogined,
  isMobilePhoneNum,
  delAllNonPrintableCharacter,
  convertArrObjListTimestamp
}


mpBMCwepysrcpagescloundAd.vue


   async getFeedData() {
      if (this.apiRes.AdKWPublished !== undefined) {
        if (this.pagination.total === this.apiRes.AdKWPublished.length) {
          wx.showToast({
            title: '亲我有底线',
            icon: 'loading',
            duration: 1500
          })
          return
        }
      }
      const q = {
        query: {
          uid: this.$parent.UID.uid,
          page: this.pagination.from,
          size: this.pagination.size
        }
      }
      const r = await api.getAdKWPublished(q)
      if (r === false) {
        return
      } else if (r.data.status !== 1) {
        wx.showToast({
          title: '亲暂无更多',
          icon: 'loading',
          duration: 1500
        })
        return
      }
      let arr = r.data.data
      arr = util.convertArrObjListTimestamp(arr, 'create_time')
      this.apiRes.AdKWPublished = this.apiRes.AdKWPublished ? this.apiRes.AdKWPublished.concat(arr) : arr
      this.pagination.total = r.data.count
      this.pagination.from += 1
      this.$apply()
    }

　　

方法: 对可读的时间格式的多样性扩展性

 暂时没有满足开闭原则

const a={
false :'123',
v:567
}
const b=false
a[b]