toString、求平均数工具类
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 }