关于JavaScript/TypeScript中的setTimeout和setInterval

ypescript是强类型语言，定义setInterval()必须定义其返回值，但是你无论用百度或者谷歌搜中文也好英文也罢，都告诉你setInterval()的返回值类型是number，

如果你将setInterval()定义成number型，会告诉你不能将类型“Timeout”分配给类型“number”，但是如果定义成所谓的“Timeout”型，也就是“NodeJS.Timeout”型初期化又成了问题

那么要这么定义：

public timer: NodeJS.Timer | null = null;

但是不能完全照搬因为这么定义的话

clearInterval(timer)时参数类型会出问题，所以要将参数强制转换成number型

也就是clearInterval(Number(timer))。

例：

数组只要含有 curTimes字段就创建一个定时器，多个定时器同时倒计时，若该时间大于当前时间则清楚该定时器

  this.list.map((itemSec, indexSec) => {
            let _this = this;
            if (itemSec.curTimes) {
              itemSec.timer = setInterval(() => {
                var my_time: any = new Date(Number(itemSec.curTimes)).getTime();
                var my_time2: any = new Date().getTime();
                var mss: any = Number(itemSec.curTimes) - Number(my_time2);
                if (Number(my_time) - Number(my_time2) <= 0) {
                  itemSec.timer && clearInterval(itemSec.timer);
                  itemSec.currentHours = 0;
                  itemSec.currentSecond = 0;
                  itemSec.currentMinutes = 0;
                  return;
                }
                var hours: any = Math.floor(
                  (mss % (1000 * 60 * 60 * 24)) / (1000 * 60 * 60)
                );
                var minutes: any = Math.floor(
                  (mss % (1000 * 60 * 60)) / (1000 * 60)
                );
                var seconds: any = Math.floor((mss % (1000 * 60)) / 1000);
                if (minutes < 10) {
                  minutes = "0" + minutes;
                }
                if (seconds < 10) {
                  seconds = "0" + Number(seconds);
                } else {
                  seconds = Number(seconds);
                }
                itemSec.currentHours = hours;
                itemSec.currentSecond = seconds;
                itemSec.currentMinutes = minutes;
              
              }, 1000);
            }
          });