Question

思路就是递归调用 setTimeout

function mySetInterval(callback, delay) {
  let timer = null
  let interval = () => {
    timer = setTimeout(()=>{
      callback()
      interval() // 递归
    }, delay)
  }
  interval() // 先执行一次
  return {
    id: timer,
    clear: () => {
      clearTimeout(timer)
    }
  }
}

let time = mySetInterval(()=>{
  console.log(1)
},1000)
setTimeout(()=>{
  time.clear()
},2000)