js 随机打乱一个数组

function randomArr(arr) {
    let len = arr.length;
    while (len) {
        let i = Math.floor(Math.random() * len--);
        [arr[i], arr[len]] = [arr[len], arr[i]];
    }
    return arr;
}

let arr = [1,2,3,4,5,6];

console.log(randomArr(arr));