为什么我的异步函数返回得太早? [英] Why is my async function returning too soon?

问题描述

我正在尝试使用异步函数在另一个函数中调用一个函数.看起来像这样:

I am trying to use an async function to call a function inside another function. It looks like this:

const getConnectionsWithEmailsHash = async () => {
    const connectionsWithEmails = await parseConnections('./tmp/connections.csv') 
    console.log(connectionsWithEmails)
    return connectionsWithEmails
}

const connectionsWithEmailsHash = getConnectionsWithEmailsHash()
console.log(connectionsWithEmailsHash) 

当我在async函数中使用console.log()时，会得到期望的哈希值，但是当我在console.log()中调用异步函数的结果时，我将得到未决的承诺.尽管异步函数的要点是，它会在调用时等待promise解析，所以我做错了什么?

When I console.log() inside the async function, I get the hash I am expecting, but when I console.log() the result of calling the async function, I get promise pending. I though the point of an async function was that it waits for the promise to be resolved when it is called, so what I am I doing wrong?

推荐答案

async 函数返回promise.这行:

async functions return promises. This line:

const connectionsWithEmailsHash = getConnectionsWithEmailsHash()

...只需将 connectionsWithEmailsHash 设置为函数返回的承诺即可.要真正获得承诺的解决方案价值，您需要:

...just sets connectionsWithEmailsHash to the promise that the function returns. To actually get the resolution value of the promise, you'd need to:

1. 在另一个 async 函数中使用 await (如果这意味着在顶层使用 async ，请参见:

1. Use await within another async function (if that means using async at the top level, see: How can I use async/await at the top level?):

const connectionsWithEmailsHash = await getConnectionsWithEmailsHash()

或

对诺言使用 then

getConnectionsWithEmailsHash()
.then(connectionsWithEmailsHash => {
    // ...use `connectionsWithEmailsHash`....
})
.catch(error => {
    // ...handle error...
})

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