public static class ArrHelper {         /// <summary>         /// 对类型为T的数组进行扩展，把满足条件的元素移动到数组的最前面         /// </summary>         /// <typeparam name="T"></typeparam>         /// <param name="arr">源数组</param>         /// <param name="match">lamda表达式</param>         /// <returns></returns>         public static bool MoveToFront<T>(this T[] arr, Predicate<T> match)         {             //如果数组的长度为0             if (arr.Length == 0)             {                 return false;             }             //获取满足条件的数组元素的索引             var index = Array.FindIndex(arr, match);             //如果没有找到满足条件的数组元素             if (index == -1)             {                 return false;             }             //把满足条件的数组元素赋值给临时变量             var temp = arr[index];             Array.Copy(arr, 0, arr, 1, index);             arr[0] = temp;             return true;         }         public static void PrintArray<T>(T[] arr)         {             foreach (var item in arr)             {                 Console.Write(item + " ");             }             Console.WriteLine();         } }

class Program {         static void Main(string[] args)         {             int[] intArr = new int[]{1, 2, 3, 4, 5};             ArrHelper.PrintArray(intArr);             intArr.MoveToFront(i => i == 3);             ArrHelper.PrintArray(intArr);             Console.ReadKey();         } }