static void Main(string[] args)
{
 int[] hs = { 1,2,3,4,5,6,7,8,9};
 int ligh = hs.Length;
 while (ligh > 0)
 {
 Console.WriteLine(hs[ligh - 1]);
 ligh -= 1;
 }
 
 Console.ReadKey();
} 

static void Main(string[] args)
{
 int[] hs = { 1,2,3,4,5,6,7,8,9};
 //倒叙打印只需要修改一下判断条件即可
 for (int i = 0; i < hs.Length; i++)
 {
 Console.WriteLine(hs[i].ToString());
 }
 
 Console.ReadKey();
} 

static void Main(string[] args)
{
 int[] hs = { 1,2,3,4,5,6,7,8,9};
 //这里用到了var关键字，匿名类型(由编译器自动推断)，你可以把它换成int
 foreach (var item in hs)
 {
 Console.WriteLine(item.ToString());
 }
 
 Console.ReadKey();
}

int i; 
for(i=1;i<=10;++i) 
{ 
  Console.WriteLine("{0}",i); 
} 

for(int i=1;i<=10;++i) 
{ 
  Console.WriteLine("{0}",i); 
}