C#数组的排序（正序逆序）

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication4
{
class Program
{
static void Main(string[] args)
{

string[] str = { "d","h","a","c","g","t","e","u","b"};

var lowtohigh = from p in str orderby p select p; //linq
str = lowtohigh.ToArray();
foreach (var item in str)
{
Console.WriteLine("正序排列" + item);//正序排列
}
//=================================================
for (int i = 0; i < str.Length/2;i ++ )
{
string temp=str[i];              //新建一个变量相互交换
str[i]=str[str.Length-i-1];
str[str.Length - i - 1] = temp;//相互交换
}
foreach (var newstr in str)
{
Console.WriteLine("逆序排列："+newstr);
}
Console.WriteLine("===================================");
//###############################################
int[] num = { 5, 78, 9, 1, 8, 4, 2, 88, 3 };
var lowtohigh1 = from p in num orderby p select p;
num = lowtohigh1.ToArray();
foreach (var num1 in num)
{
Console.WriteLine(num1);//正序排列
}

for (int i = 0; i < num.Length / 2;i++ )
{
int temp =num[i];             //新建一个变量相互交换
num[i] = num[num.Length - i - 1];
num [num.Length - i - 1] = temp;//相互交换
}
foreach (var newnum in num)
{
Console.WriteLine("逆序排列：" + newnum);
}
Console.WriteLine("===================================");

}
}
}