.NET from-where-select用法

���接上示例代码进行说明：

1. from-where-select的用法：

int[] arr = {3, 4, 5, 6, 7, 8, 9};int[] res = (from a in arr                where a > 4 && a  Console.WriteLine($"item");

2. 运行结果：

5678

3. 以上from-where-select用法可以for用法解读：

for (int i = 0; i  4 && res[i]