c#的三个问题（应该很简单，希望有人来解答）

Question

１．for循环，用substring
２．用replace
３．不明白什么意思

Answer 1

1.for语句我用过了．你说的substring给个例子来看看．
２.第二个经过提示也做出来啦．
３．第三个大家在帮帮忙吧．
谢谢啦．

Answer 2

1、
            string inStr = Console.ReadLine();
            char[] inChar = inStr.ToCharArray();
            Array.Reverse(inChar);
            string outStr = new string(inChar);
            Console.Write(outStr);
            Console.ReadLine();
2、
            string inStr = Console.ReadLine();
            string outStr = inStr.Replace("no", "yes");
            Console.Write(outStr);
            Console.ReadLine();3、没看明白

Answer 3

用 split函数 以空格分割 每个词加好引号再合并到一起

Answer 4

2、
   string inStr = Console.ReadLine();
            string outStr = inStr.ToLower().Replace("yes", "no");
            Console.Write(outStr);
            Console.ReadLine();

Answer 5

1
static void Main()
{
 string strResult=DostrRev(" hello world!");
Console.WriteLine(" fa zhuan shu chu wei {0}",strResult);
}
string DostrRev(string strTest)
{
if(strTest.Lenght==1)
return strTest;
string strResult=strTest.Substring(strTest.Lenght-1,1)
strResult+=DostrRev(strTest.Substring(0,strTest.lenght-1));
return strResult;
}

Answer 6

3.string inStr = Console.ReadLine();
string repStr = "\"";
string outStr = Regex.Replace(inStr,"^ +","",RegexOptions.IgnoreCase);
outStr = Regex.Replace(outStr," +$","",RegexOptions.IgnoreCase);
outStr = repStr + outStr + repStr;
            outStr = Regex.Replace(outStr," +",repStr+" "+repStr,RegexOptions.IgnoreCase);
            Console.Write(outStr);
            Console.ReadLine();