max in array java

                                    public static String max(String[] arr) {
  String result = arr[0];
  for (int i = 1; i < arr.length; ++i) {
    if (result.compareTo(arr[i]) < 0) result = arr[i];
  }
  return result;
}

                                    public static double max(double[] arr) {
  double result = Double.NEGATIVE_INFINITY;
  for (int i = 0; i < arr.length; ++i) {
    if (result < arr[i]) result = arr[i];
  }
  return result;
}

                                    public static double arrayMax(double[] arr) {
    double max = Double.NEGATIVE_INFINITY;

    for(double cur: arr)
        max = Math.max(max, cur);

    return max;
}

                                    Integer[] num = { 2, 4, 7, 5, 9 };
        // using Collections.min() to find minimum element
        // using only 1 line.
        int min1 = Collections.min(Arrays.asList(num));

        // using Collections.max() to find maximum element
        // using only 1 line.
        int max1 = Collections.max(Arrays.asList(num));
        System.out.println(min1); // 2 
        System.out.println(max1); // 9

                                    public static double max(double[] arr) {
  double result = arr[0];
  for (int i = 1; i < arr.length; ++i) {
    if (result < arr[i]) result = arr[i];
  }
  return result;
}