考虑以下代码:

var result1;
var result1Promise = getSomeValueAsync().then(x => result1 = x);

var result2;
var result2Promise = getSomeValueAsync().then(x => result2 = x);

await Promise.all([result1Promise, result2Promise]);

// Are result1 and result2 guaranteed to have been set at this point?

console.log(result1 + result2); // Will this always work? Or could result1 and/or result2 be undefined because then() has not been executed yet?

当我使用then()方法时,是否保证已按顺序执行?例如。在Promise.all解决之后,then()将不会立即执行?

在Chrome中似乎可以正常工作,但是我真正要寻找的是保证它在某些规格下始终可以工作吗?

我宁愿不使用Promise.all(...)。then(某些回调),因为那样我会再次使用回调...

最佳答案

您可以直接使用 Promise.all 的返回值:

const p1 = getSomeValueAsync();
const p2 = getSomeValueAsync();

const [result1, result2] = await Promise.all([p1, p2]);

console.log(result1 + result2);

关于javascript - 如何正确使用Promise.all?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/56542219/

10-12 07:08