从函数返回承诺值

本文介绍了从函数返回承诺值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我试图使该递归函数返回一个promise值，我不知道该怎么做，我尝试过以不同的方式编写它，但是它们都以 search 结尾正在 undefined

I am trying to make this recursive function return a promise value, I don't know how to go about doing it, I have tried writing it in different ways but they all ended up with search being undefined

public search(message: Message) { let search: string; const filter = (msg: Message) => msg.author.id === message.author.id; message.channel.send('Enter search term').then(msg => { message.channel.awaitMessages(filter, { max: 1 }) .then(collected => { if (collected.first()!.content === 'Test') this.search(message); msg.delete() collected.first()!.delete() search = collected.first()!.content }) }) }) return search; // Variable 'search' is used before being assigned.ts(2454) }

推荐答案

您是否考虑过使用异步功能?仅此一点就可以使您的代码更易于调试和理解.

Have you considered using an async function? That alone would make your code easier to debug and understand.

public async search(message: Message): Promise<any> { const filter = (msg: Message) => msg.author.id === message.author.id; const msg = await message.channel.send('Enter search term'); const collected = await message.channel.awaitMessages(filter, { max: 1 }); if (collected.first()!.content === 'Test') return this.search(message); msg.delete(); collected.first()!.delete(); const search = collected.first()!.content; return search; }

在这里， search 被定义为const并立即返回，这对于编译器来说很好.我没有使用变量来保存嵌套的 this.search 调用的返回值，但是如果您决定在计算实际结果之后执行更多代码，则可能必须这样做.

Here, search is defined as a const and immediately returned, and that's fine to the compiler. I didn't use a variable to save the return value of the nested this.search call, but you may have to if you decide to execute more code after calculating the actual result.