如何“重复"一个数组n次 [英] How to 'repeat' an array n times

问题描述

在python中，您可以执行以下操作:

In python you can do:

arr = [1,2,3] * 3
print(arr)

输出:

[1,2,3,1,2,3,1,2,3]

在Java脚本中是否有一种简洁的方法?我能想到的最好的是这样的:

Is there a concise way of doing this in java script? The best I can think of is something like:

let arr2 = [...arr, ...arr, ...arr]

但是如果我想做100次，那将是不切实际的.在python中，我会将其乘以100.

but if I wanted to do this 100 times it would be impractical. In python I would just multiply it by 100.

推荐答案

您可以执行以下操作:

var repeated = [].concat(... new Array(100).fill([1, 2, 3]));

这将创建一个给定长度的数组(此处为100)，并用要重复的数组填充它([1, 2, 3]).然后将该数组作为参数列表传播到[].concat().

That creates an array of a given length (100 here) and fills it with the array to be repeated ([1, 2, 3]). That array is then spread as the argument list to [].concat().

哦，等一下

var repeated = new Array(100).fill([1, 2, 3]).flat();

会短一些.

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