title: Convert String To camelCase from TitleCase C#
body: <p>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.</p>
  
  <pre><code>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();
      }
  }
  </code></pre>
  
  <p>Results: ZebulansNightmare</p>
  
  <p>Desired Results: zebulansNightmare</p>
  
  <p>UPDATE:</p>
  
  <pre><code>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();
      }
  }
  </code></pre>
  
  <p>Produces the desired output</p>