为什么清除不掉定时器？clearTimeout不生效

Answer 1

let timeout = null;let a = 1;function intervalFun() {  clearTimeout(timeout);  timeout = setTimeout(function () {    console.log(1);    intervalFun()  }, 1000);}function cancelInterval() {  console.log(timeout);  clearTimeout(timeout);}function reStart(){  cancelInterval();  intervalFun();}