异步函数

# 异步函数

改造前

const fn1 = () =>{
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(1);
    }, 300);
  });
}
const fn2 = () =>{
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      resolve(2);
    }, 600);
  });
}
const fn = () =>{
   fn1().then(res1 =>{
      console.log(res1);// 1
      fn2().then(res2 =>{
        console.log(res2)
      })
   })
};

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改造后

const fn = async () =>{
  const res1 = await fn1();
  const res2 = await fn2();
  console.log(res1);// 1
  console.log(res2);// 2
}

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如果是并发请求，可以使用Promise.all()

const fn = () =>{
   Promise.all([fn1(),fn2()]).then(res =>{
       console.log(res);// [1,2]
   }) 
}

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上次更新: 2024/08/14, 04:14:33

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