在箭头函数中返回扩展数组 [英] Return spreaded array in arrow function

问题描述

假设我具有这种类型的数组：

Let's assume i have this type of array:

[[1，2]，[3，4]]

我需要做的是在较高层上获取嵌套元素，使其看起来像：

What i need to do is to get nested elements on the higher layer, to make it look like:

[1、2、3、4]

我正在尝试以实用的方式实现这一目标，因此代码看起来像这样：

I am trying to reach that in functional way, so the code look's like this:

const arr = [ [1, 2], [3, 4] ]
const f = Array.from(arr, x => ...x)

但是出现意外令牌... 错误。那么正确的方法是什么？

But that comes up with Unexpected token ... error. So what's the way to do it right?

推荐答案

您可以使用 flat 数组方法：

const inp = [ [1, 2], [3, 4] ];

console.log(inp.flat());

在您的情况下，扩展语法不是您可以使用的运算符，所以这就是错误的原因。

In your case, the spread syntax is not an operator that you can use in that way, that's why the error.

@MarkMeyer正确指出请注意，Edge和Internet Explorer尚不支持 flat 。在这种情况下，您可以使用 reduce 寻求解决方案：

As @MarkMeyer correctly pointed out in the comments, the flat is not supported yet by Edge and Internet Explorer. In this case you could go for a solution with reduce:

const inp = [[1,2], [3,4]];
console.log(inp.reduce((acc, val) => acc.concat(...val), []));

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