写个方法随机打乱一个数组

两个思路

• 随机交换

function shuffle(arr) {    arr.forEach((_, idx) => {        const targetIdx = Math.floor(Math.random() * arr.length)        ;[arr[idx], arr[targetIdx]] = [arr[targetIdx], arr[idx]]    })    return arr}shuffle([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])// => [6, 4, 1, 8, 5, 2, 10, 9, 3, 7] or else

• 打乱下标（慢了 300-1000 倍左右）

function shuffleSubscript(n) {    const arr = new Array(n)    for (let i = 0; i < n; i++) {        let val        do val = Math.floor(Math.random() * n)        while (arr.includes(val))        arr[i] = val    }    return arr}function shuffle(arr) {    return shuffleSubscript(arr.length).map(s => arr[s])}shuffle([1, 2, 3, 4, 5, 6, 7, 8, 9, 10])// => [7, 4, 5, 8, 6, 3, 1, 2, 10, 9] or else