random suffling java

1void shuffle(int [] arr) {
2        for (int i = 0; i < arr.length; i++) {
3            int index = (int) (Math.random() * arr.length);
4            int temp = arr[i];
5            arr[i] = arr[index];
6            arr[index] = temp;
7        }
8    }

1for (int i = myList.length - 1; i > 0; i--){
2            int j = (int) (Math.random() * (i + 1));
3
4            double temp = myList[i];
5            myList[i] = myList[j];
6            myList[j] = temp;
7        }