Js操作取最深一级的值递归

let s = {
  id: 1, name: 'hah ', pid: {
    id: 5, pid: {
      id: 6, name: 4
    }
  }
}
let id = s;
while(id &&id.pid){
  id = id.pid
}
console.log(id) //{id: 6, name: 4}