C# 大小寫轉換

C#通過ToUpper()方法將字符串轉換成大寫，代碼如下：

string sentence= "this is in upper case.";

Console.WriteLine(sentence.ToUpper());

C#通過ToLower()方法將字符串轉換成小寫，代碼如下：

string sentence= "this is in Lower case.";

Console.WriteLine(sentence.ToLower());