如何在React中等待多个异步等待请求

Question

I am wanting to do something like the following in a React component:

const someArray = [/*stuff*/]
const results = []
someArray.forEach(async item => {

  const result = await someAsyncFunction(item)
  results.push(result)
})

How can I know when all the results have returned then do something?

If I was using $q, in AngularJS, I could do

var results = []
someArray.forEach(function(item) {
  var result = someAsyncFunctionThatReturnsAPromise(item);
  results.push(result);
});

$q.all(results).then(function() {
  // do something
});

Answer 1

You'd do exactly the same thing as if it wasn't a React component:

Promise.all(someArray.map(someAsyncFunction)).then(results => {
  // do stuff with results
});

Of course you can also use q , which $q is based on. It's up to you.

Answer 2

除了Felix的答案，在async函数中，你还可以await Promise.all()的结果，所以：

const results = await Promise.all(someArray.map(someAsyncFunction));