codemeit

C# To Upper Case First Letter of a String

Utilize a simple extension method to capitalize the first letter of a string.

public class Program
    {
        static void Main(string[] args)
        {
            string s = "toUpperFirstLetter";
            // ToUpperFirstLetter is the extension method defined below
            Console.WriteLine( s.ToUpperFirstLetter() );
            // output:  ToUpperFirstLetter

            Console.ReadLine();
        }
    }
    
    // string extension class
    public static class StringExtension
    {
        // string extension method ToUpperFirstLetter
        public static string ToUpperFirstLetter(this string source)
        {
            if (string.IsNullOrEmpty(source))
                return string.Empty;
            // convert to char array of the string
            char[] letters = source.ToCharArray();
            // upper case the first char
            letters[0] = char.ToUpper(letters[0]);
            // return the array made of the new char array
            return new string(letters);
        }
    }