快速排序

let arr1 = [1, 23, 4, 2, 5, 6, 90, 0, 2, 55, 1.3];

function quickSort(arr) {
    if (arr.length <= 1) {
        return arr;
    }
    let pivotIndex = Math.floor(arr.length / 2),
        pivot = arr.splice(pivotIndex, 1)[0],
        left = [],
        right = [];
    for (let i = 0; i < arr.length; i++) {
        if (arr[i] < pivot) {
            left.push(arr[i]);
        } else {
            right.push(arr[i]);
        }
    }
    return quickSort(left).concat(pivot, quickSort(right));
}

quickSort(arr1); //[0, 1, 1.3, 2, 2, 4, 5, 23, 55, 90]