Javascript 获取数组中的第一个和最后一个元素，ES6 方式
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Get first and last elements in array, ES6 way
提问by Nicholas
let array = [1,2,3,4,5,6,7,8,9,0]
let array = [1,2,3,4,5,6,7,8,9,0]
Documentation is something like this
文档是这样的
[first, ...rest] = arraywill output 1 and the rest of array
[first, ...rest] = array将输出 1 和数组的其余部分
Now is there a way to take only the first and the last element 1 & 0with Destructuring
现在是有办法只有采取第一和最后一个元素1 & 0与Destructuring
ex: [first, ...middle, last] = array
前任： [first, ...middle, last] = array
I know how to take the first and last elements the other way but I was wondering if it is possible with es6
我知道如何以另一种方式获取第一个和最后一个元素，但我想知道 es6 是否可行
回答by Pranav C Balan
The rest parametercan only use at the end not anywhere else in the destructuring so it won't work as you expected.
在其余的参数可以在最后没有任何其他地方的解构，这样就不会工作，如你预期只能使用。
Instead, you can destructorcertain properties(an array is also an object in JS), for example, 0for first and index of the last element for last.
相反，您可以析构某些属性（数组在 JS 中也是一个对象），例如，0对于 first 和 last 元素的最后一个元素的索引。
let array = [1,2,3,4,5,6,7,8,9,0]
let {0 : a ,[array.length - 1] : b} = array;
console.log(a, b)Or its better way to extract length as an another variable and get last value based on that ( suggested by @Bergi) , it would work even there is no variable which refers the array.
或者它更好的方法是将长度提取为另一个变量并基于该变量获取最后一个值（@Bergi 建议），即使没有引用数组的变量，它也可以工作。
let {0 : a ,length : l, [l - 1] : b} = [1,2,3,4,5,6,7,8,9,0];
console.log(a, b)