递归方法求阶乘字符串反转(网上找的，仅自用，非原创)

using System;
class UsingRecursive
{
static void Main()
{
int intResult;
string strResult;
UsingRecursive myURec=new UsingRecursive ();
intResult=myURec.DoFactorial (10);
Console.WriteLine ("10的阶乘是:"+intResult);
strResult=myURec.DoStrRev ("This is a test string.");
Console.WriteLine ("字符串反转后为:"+"\n"+strResult);
}
int DoFactorial(int pF)
{
int result=0;
if(pF==1)
return 1;
result=DoFactorial(pF-1)*pF;
return result;
}
string DoStrRev(string strTest)
{
if(strTest.Length==1)
return strTest;
string strResult=strTest.Substring (strTest.Length-1,1);
strResult+=DoStrRev(strTest.Substring (0,strTest.Length-1));
return strResult;
}
}