C#获取一个数组中的最大值、最小值、平均值
1.给出一个数组
1 int[] array = new int[] { 1,2,4,3,0,-1,34,545,2,34};
2.数组Array自带方法
本身是直接可以调用Min(),Max(),Average()方法来求出 最小值、最大值、平均值
1 Console.WriteLine("--------------Array自身方法-----------------"); 2 Console.WriteLine("Min:{0}",array.Min()); 3 Console.WriteLine("Max:{0}", array.Max()); 4 Console.WriteLine("Average:{0}", array.Average());
输出结果：
1 --------------Array自身方法----------------- 2 Min:-1 3 Max:545 4 Average:62.4
3.编码实现
最小值
1 /// <summary> 2 /// 最小值 3 /// </summary> 4 /// <param name="array"></param> 5 /// <returns></returns> 6 public static int Min(int[] array) 7 { 8 if (array == null) throw new Exception("数组空异常"); 9 int value = 0; 10 bool hasValue = false; 11 foreach (int x in array) 12 { 13 if (hasValue) 14 { 15 if (x < value) value = x; 16 } 17 else 18 { 19 value = x; 20 hasValue = true; 21 } 22 } 23 if (hasValue) return value; 24 throw new Exception("没找到"); 25 }
最大值
1 /// <summary> 2 /// 最大值 3 /// </summary> 4 /// <param name="array"></param> 5 /// <returns></returns> 6 public static int Max(int[] array) 7 { 8 if (array == null) throw new Exception("数组空异常"); 9 int value = 0; 10 bool hasValue = false; 11 foreach (int x in array) 12 { 13 if (hasValue) 14 { 15 if (x > value) 16 value = x; 17 } 18 else 19 { 20 value = x; 21 hasValue = true; 22 } 23 } 24 if (hasValue) return value; 25 throw new Exception("没找到"); 26 }
平均值
1 /// <summary> 2 /// 平均值 3 /// </summary> 4 /// <param name="source"></param> 5 /// <returns></returns> 6 public static double? Average(int[] array) 7 { 8 if (array == null) throw new Exception("数组空异常"); 9 long sum = 0; 10 long count = 0; 11 checked 12 { 13 foreach (int? v in array) 14 { 15 if (v != null) 16 { 17 sum += v.GetValueOrDefault(); 18 count++; 19 } 20 } 21 } 22 if (count > 0) return (double)sum / count; 23 return null; 24 }
4.测试输出
测试代码
1 static void Main(string[] args) 2 { 3 int[] array = new int[] { 1,2,4,3,0,-1,34,545,2,34}; 4 5 Console.WriteLine("--------------Array自身方法-----------------"); 6 Console.WriteLine("Min:{0}",array.Min()); 7 Console.WriteLine("Max:{0}", array.Max()); 8 Console.WriteLine("Average:{0}", array.Average()); 9 10 Console.WriteLine("---------------内部实现方法------------------"); 11 int min = Program.Min(array); 12 int max = Program.Max(array); 13 double? average = Program.Average(array); 14 Console.WriteLine("Min:" + min); 15 Console.WriteLine("Max:" + max); 16 Console.WriteLine("Average:" + average); 17 Console.Read(); 18 }
输出结果
以上代码也是从.NET Framework中摘出来的，实际上 Array的自带求最大值、最小值、平均值的算法就是这样做的，在.NET Framework源码中可以看到