秒表计时器（Timeout 实现 Interval）
const timerIdList = {};
mySetInterval(fn: (time: number) => void, delay: number) {
const key = Symbol();
const interval = () => {
const start = Date.now();
this.timerIdList[key] = setTimeout(() => {
const end = Date.now();
const excuTime = end - start;
try {
fn(excuTime);
} catch (e) {
throw e.toString();
}
interval();
}, 1000, false);
};
setTimeout(interval, delay);
return key;
}
myClearInterval(key: symbol) {
if (key in this.timerIdList) {
clearTimeout(this.timerIdList[key]);
delete this.timerIdList[key];
}
}