function insertionSort(arr) {
    for(let i = 1; i < arr.length; i++) {
        let currentVal = arr[i];
        let j = i - 1;
        while(j >= 0 && currentVal < arr[j]) {
            arr[j+1] = arr[j];
            j--;
        }
        arr[j+1] = currentVal;
    }
    return arr;
}