C#獲取一個數組中的最大值、最小值、平均值

1.給出一個數組

1             int[] array = new int[] { 1,2,4,3,0,-1,34,545,2,34};

2.數組Array自帶方法

本身是直接可以調用Min(),Max(),Average()方法來求出 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());

輸出結果：

1 --------------Array自身方法-----------------
2 Min:-1
3 Max:545
4 Average:62.4

3.編碼實現

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("數組空異常");
 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("沒找到");
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("數組空異常");
 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("沒找到");
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("數組空異常");
 9             long sum = 0;
10             long count = 0;
11             checked
12             {
13                 foreach (int? v in array)
14                 {
15                     if (v != null)
16                     {
17                         int a = v.GetValueOrDefault();
18                         sum += v.GetValueOrDefault();
19                         count++;
20                     }
21                 }
22             }
23             if (count > 0) return (double)sum / count;
24             return null;
25         }

4.測試輸出

測試代碼

 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("---------------內部實現方法------------------");
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         }

輸出結果

以上代碼也是從.NET Framework中摘出來的，實際上 Array的自帶求最大值、最小值、平均值的算法就是這樣做的，在.NET Framework源碼中可以看到

C#獲取一個數組中的最大值、最小值、平均值