異步箭頭功能的語法

本文翻譯自：Syntax for async arrow function

I can mark a javascript function as "async" (ie returning a promise) with the async keyword. 我可以使用async關鍵字將javascript函數標記爲“異步”（即返回承諾）。 Like this: 像這樣：

async function foo() {
  // do something
}

What is the equivalent syntax for arrow functions? 箭頭功能的等效語法是什麼？

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#1樓

參考：https://stackoom.com/question/2uGvO/異步箭頭功能的語法

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#2樓

Async arrow functions look like this: 異步箭頭函數如下所示：

const foo = async () => {
  // do something
}

Async arrow functions look like this for a single argument passed to it: 傳遞給它的單個參數的異步箭頭函數如下所示：

const foo = async evt => {
  // do something with evt
}

The anonymous form works as well: 匿名形式也可以使用：

const foo = async function() {
  // do something
}

An async function declaration looks like this: 異步函數聲明如下所示：

async function foo() {
  // do something
}

Using async function in a callback : 在回調中使用異步函數：

const foo = event.onCall(async () => {
  // do something
})

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#3樓

This the simplest way to assign an async arrow function expression to a named variable: 這是將async箭頭函數表達式分配給命名變量的最簡單方法：

const foo = async () => {
  // do something
}

_{(Note that this is not strictly equivalent to async function foo() { } . Besides the differences between the function keyword and an arrow expression , the function in this answer is not "hoisted to the top" .) （請注意，這並不嚴格等同於async function foo() { } 。除了function關鍵字和箭頭表達式之間的區別之外，此答案中的函數沒有“提升到頂部” 。）}

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#4樓

You may also do: 您也可以這樣做：

 YourAsyncFunctionName = async (value) => {

    /* Code goes here */

}

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#5樓

Immediately Invoked Async Arrow Function: 立即調用異步箭頭功能：

(async () => {
    console.log(await asyncFunction());
})();

Immediately Invoked Async Function Expression: 立即調用異步函數表達式：

(async function () {
    console.log(await asyncFunction());
})();

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#6樓

Async Arrow function syntax with parameters 帶參數的異步箭頭函數語法

const myFunction = async (a, b, c) => {
   // Code here
}