动态显示当前时间

每秒请求一次当前时间

<li class="time">{{nowTime}}</li>
data() {
    return {
      nowTime: new Date()
    }
  },
 mounted: function () {
    this.timer = setInterval(() => {
      this.nowTime = dateFormat(new Date())
    }, 1000)
}

销毁的时候清除定时器

beforeDestroy() {
 if (this.timer) {
    clearInterval(this.timer);
  }
},

dateFormat方法

export const dateFormat = (date) => {
  var year = date.getFullYear();
  var month = date.getMonth() + 1 < 10 ? "0" + (date.getMonth() + 1) : date.getMonth() + 1;
  var day = date.getDate() < 10 ? "0" + date.getDate() : date.getDate();
  var hours = date.getHours() < 10 ? "0" + date.getHours() : date.getHours();
  var minutes = date.getMinutes() < 10 ? "0" + date.getMinutes() : date.getMinutes();
  var seconds = date.getSeconds() < 10 ? "0" + date.getSeconds() : date.getSeconds();
  let week = date.getDay(); // 星期
  let weekArr = ["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六",];
  return (year + "年" + month + "月" + day + "日 " + hours + ":" + minutes + ":" + seconds + " " + weekArr[week]);
}