Convert String To camelCase from TitleCase C#

Question

I have a string that I converted to a TextInfo.ToTitleCase and removed the underscores and joined the string together. Now I need to change the first and only the first character in the string to lower case and for some reason, I can not figure out how to accomplish it. Thanks in advance for the help.

class Program {     static void Main(string[] args)     {         string functionName = "zebulans_nightmare";         TextInfo txtInfo = new CultureInfo("en-us", false).TextInfo;         functionName = txtInfo.ToTitleCase(functionName).Replace('_', ' ').Replace(" ", String.Empty);         Console.Out.WriteLine(functionName);         Console.ReadLine();     } } 

Results: ZebulansNightmare

Desired Results: zebulansNightmare

UPDATE:

class Program {     static void Main(string[] args)     {         string functionName = "zebulans_nightmare";         TextInfo txtInfo = new CultureInfo("en-us", false).TextInfo;         functionName = txtInfo.ToTitleCase(functionName).Replace("_", string.Empty).Replace(" ", string.Empty);         functionName = $"{functionName.First().ToString().ToLowerInvariant()}{functionName.Substring(1)}";         Console.Out.WriteLine(functionName);         Console.ReadLine();     } } 

Produces the desired output

Answer 1

You just need to lower the first char in the array. See this answer

Char.ToLowerInvariant(name[0]) + name.Substring(1) 

As a side note, seeing as you are removing spaces you can replace the underscore with an empty string.

.Replace("_", string.Empty) 

Answer 2

Implemented Bronumski's answer in an extension method (without replacing underscores).

 public static class StringExtension  {      public static string ToCamelCase(this string str)      {                              if(!string.IsNullOrEmpty(str) && str.Length > 1)          {              return char.ToLowerInvariant(str[0]) + str.Substring(1);          }          return str;      }  }   //Or   public static class StringExtension  {      public static string ToCamelCase(this string str) =>          string.IsNullOrEmpty(str) || str.Length < 2          ? str          : char.ToLowerInvariant(str[0]) + str.Substring(1);  } 

and to use it:

string input = "ZebulansNightmare"; string output = input.ToCamelCase();