使用es6 spread来连接多个数组

Question

我们都知道你可以这样做:

let arr1 = [1,2,3];
let arr2 = [3,4,5];
let arr3 = [...arr1, ...arr2]; // [1,2,3,3,4,5]

但是,如何使这种动态连接N阵列？

Answer 1

一种选择是使用reduce:

let arrs = [[1, 2], [3, 4], [5, 6]];
arrs.reduce((a, b) => [...a, ...b], []);

当然,这是一个缓慢的解决方案(二次时间).或者,如果您可以使用Lodash,您可以_.flatten完全按照自己的意愿行事,并且更有效(线性时间).

编辑

或者,改编自下面的Xotic750评论,

[].concat(...arrs);

哪个应该是有效的(线性时间).

Answer 2

另一个选择可能是:

const nArrays = [
  [1, 2, 3, 4, 5],
  [6, 7, 8, 9],
  [10, 11]
];
const flattened = [].concat(...nArrays);
console.log(flattened)

Answer 3

let fruits = ["apples", "bananas", "pears"];
let vegetables = ["corn", "potatoes", "carrots"];

let produce = [...fruits, ...vegetables];


console.log(produce);