How do I Capitalize First Letter of String in C#

public static string ToTitleCase(string str)
   {
       string result = str;
       if (!string.IsNullOrEmpty(str))
       {
           var words = str.Split(' ');
           for (int index = 0; index < words.Length; index++)
           {
               var s = words[index];
               if (s.Length > 0)
               {
                   words[index] = s[0].ToString().ToUpper() + s.Substring(1);
               }
           }
           result = string.Join(" ", words);
       }
       return result;
   }

Input : String strR = ToTitleCase("c sharp corner");

output: C Sharp Corner

Example 2 :

public static string FirstCharToUpper(string input)
   {
       if (String.IsNullOrEmpty(input))
           throw new ArgumentException("Error  !");
       return CultureInfo.CurrentCulture.TextInfo.ToTitleCase(input.ToLower());
   }