反转

1、比如 string Str="I am a boy"如何这样输出string StrChanged="boy a am I",前些天看到了，今天找不到了！

string Str="I am a boy"

string StrChanged=string.Empty;

0 0

string[] Arr = Str.Split(' ');
for (int i = Arr.Length; i > 0; i--)
{
StrChanged += Arr[i - 1] + " ";
}
Console.WriteLine(StrChanged.Trim());
Console.Read();

如果比较长，改用StringBuilder效率会高一些：
string Str = "I am a boy";
StringBuilder StrChanged = new StringBuilder(512);

string[] Arr = Str.Split(' ');
for (int i = Arr.Length; i > 0; i--)
{
StrChanged.Append(Arr[i - 1]).Append(" ");
}
Console.WriteLine(StrChanged.ToString().Trim());
Console.Read();