
1 /* 构造器私有化
2 */
3 private ArraysUtils(){}
4
5 // toString()工具类 静态方法、工具方法
6 public static String toString(int[] arr){
7 if (arr != null){
8 String result = "[";
9 for (int i = 0; i < arr.length; i++) {
10 result += (i == arr.length -1 ? arr[i] : arr[i] + ", ");
11 }
12 result += "]";
13 return result;
14 }else {
15 return null;
16 }
17
18 }
19
20 // 求平均分。静态方法工具方法
21 public static double average(int[] arr){
22 int max = arr[0];
23 int min = arr[0];
24 int mean = 0;
25 for (int i = 0; i < arr.length; i++) {
26 if (arr[i] > max){
27 max = arr[i];
28 }
29 if (arr[i] < min){
30 min = arr[i];
31 }
32 mean += arr[i];
33 }
34
35 return (mean - max - min) / (arr.length - 2) * 1.0;
36 }
1 public static void main(String[] args) {
2 int[] arr = {10, 20, 30};
3 System.out.println(arr);
4 System.out.println(ArraysUtils.toString(arr));
5 System.out.println(ArraysUtils.average(arr));
6
7 }