如何从javascript承诺中获取价值? [英] how to get value from javascript promise?

问题描述

我有一个具有以下值的 userBalance 承诺对象:

I have a userBalance promise object with following values:

> userBalance
Promise {
'100000000000000000',
domain:
 Domain {
   domain: null,
   _events:
    { removeListener: [Function: updateExceptionCapture],
      newListener: [Function: updateExceptionCapture],
      error: [Function: debugDomainError] },
   _eventsCount: 3,
   _maxListeners: undefined,
   members: [] } }

问题是，我无法从中获得 100000000000000000.有办法吗?

the problem is, i cannot get that 100000000000000000 from it. is there a way to do so?

推荐答案

唯一获取 promise 的解析值的方法(即使它已经解析)是使用 promise，通过 then 或 await:

The only way to get the resolution value of a promise (even if it's already resolved) is to consume the promise, via then or await:

userBalance.then(value => {
    // ...use `value`; note this will be called asynchronously
});

或在 async 函数中:

const value = await userBalance; // Note this will be asynchronous

在这两种情况下，加上错误处理，除非您将结果承诺传递给其他可以处理它的东西.

In both cases, plus error handling unless you're passing the resulting promise onto something else that will handle it.

这篇关于如何从javascript承诺中获取价值?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！