A left rotation operation on an array shifts each of the array's elements 1 unit to the left.

RotateLeftArray.java

    static int[] rotLeft(int[] a, int d) {
        int [] rotated = new int[a.length];

        for (int i = 0; i <= a.length - 1; i++) {
            rotated[i] = a[(i + d) % a.length];
        }
        return rotated;
    }