// let timer2=0;
let timer2=setInterval(function(){
let timer=setInterval(function(){
window.clearInterval(timer)
for(let i=0;i<5;i++){
console.log(i)
if(i>=4){
self.clearInterval(timer)
}
}
},20)
console.log(timer2,'',timer)
},2000)
全部代码了·
