在数组上映射异步函数 [英] Map async functions over an array

问题描述

我正在尝试在数组上映射一个异步函数，我希望达到这样的效果:

I am trying to map an async function over an array, I hope to achieve such effect:

const result = orgs.map(org => 
  f(org)
    .then(res => return res))
// now result should be an array of res
console.log(result)

这行不通，所以我尝试了另一种方法:

This would not work, so I tried another way:

const result = []
orgs.map(org => 
  f(org)
    .then(res => result.push(res)))
// now result should be an array of res
console.log(result)

仍然，这是行不通的.

但是我可以通过以下方式打印出结果:

But I can print out the result by doing:

orgs.map(org => 
  f(org)
    .then(res => console.log(res)))

关于这种行为如何发生的任何想法?

Any ideas on how this behavior happens?

我也在链接数组上使用 find-rss 包

Also I am using find-rss package over an array of links

推荐答案

，您可以使用Promise.all()汇总多个Promise的结果.Promise是非常有用的JavaScript.

you can use Promise.all() to aggregate the results of multiple promises. Promise is very useful is javascript.

var p1 = Promise.resolve(3);
var p2 = 1337;
var p3 = new Promise((resolve, reject) => {
  setTimeout(resolve, 100, 'foo');
}); 

Promise.all([p1, p2, p3]).then(values => { 
  console.log(values); // [3, 1337, "foo"] 
});

这是一个简单的示例，众所周知，您的组织结构图结果是一个promise数组，因此您可以使用Promise.all来获取您想要的东西

this is a simple example, as u known, your orgs map result is an promise array, so you can use Promise.all to get what u want

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