定时器在js里面封装如何抛出返回结果

Question

export const timer = (time,fun) => {
let timeId = setTimeout (() => {
fun()
},time)
}

Answer 1

export const timer = (time,fun) => {
  return new Promise((resolve) => {
    let timeId = setTimeout(() => {
      resolve(fun());
      clearTimeout(timeId);
    }, time);
  });
}

timer(1000, () => "123").then(res => console.log(res));