convert letters on phone to numbers using .NET

Introduction

If we observe the phone keypad, the phone numbers are mapped to letters as 2 - ABC , 3 -DEF , 4-GHI, 5-JKL, 6-MNO, 7-PQRS, 8-TUV, 9-WXYZ . In this snippet we will write a program which converts letters on phone to numbers using .NET.

Program:

class PhoneLetterToNumberConversion
    {
        static void Main(string[] args)
        {
            Dictionary<char, char> dicPhoneNoLetterMap = new Dictionary<char, char>() {      
            { 'A', '2' }, { 'B', '2' }, { 'C', '2' },
            { 'D', '3' }, { 'E', '3' }, { 'F', '3' },
            { 'G', '4' }, { 'H', '4' }, { 'I', '4' },
            { 'J', '5' }, { 'K', '5' }, { 'L', '5' }, 
            { 'M', '6' }, { 'N', '6' }, { 'O', '6' },
            { 'P', '7' }, { 'Q', '7' }, { 'R', '7' }, { 'S', '7' },
            { 'T', '8' }, { 'U', '8' }, { 'V', '8' },
            { 'W', '9' }, { 'X', '9' }, { 'Y', '9' }, { 'Z', '9' }
            };
            Console.WriteLine(ConvertLettersToPhoneNumbers("ADHK", dicPhoneNoLetterMap));
            Console.WriteLine(ConvertLettersToPhoneNumbers("DOTNETMIRROR", dicPhoneNoLetterMap));
            Console.Read();
        }

        static string ConvertLettersToPhoneNumbers(string letters, Dictionary<char, char> dicPhoneNoLetterMap)
        {
            char[] numbersChrArray = new char[letters.Length]; // create new char array with length of input string
            for (int i = 0; i < numbersChrArray.Length; i++)
            {
                char number;
                bool hasValue = dicPhoneNoLetterMap.TryGetValue(letters[i], out number);//check dictionary has Key Value
                if (hasValue)
                {
                    numbersChrArray[i] = number;
                }
                else
                {
                    numbersChrArray[i] = letters[i];
                }
            }
            string finalNumber = new string(numbersChrArray);
            return finalNumber;
        }
    }

Output:

"ADHK" - 2345

"DOTNETMIRROR" - 368638647767