Reverse integer - recursive solution

reverseInteger_recursiveSolution.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConvertIntToString
{
    /// <summary>
    /// July 4, 2017
    /// recursive solution 
    /// </summary>
    class Program
    {
        static void Main(string[] args)
        {
            var result = convertToString(-324);           
        }

        // Write a function that converts an int into its alpha-numeric equivalent represented 
        // as a null terminated string. The function should accept an int as input and return 
        // a string as output. For instance, calling the function with an int value of 324 would 
        // return a null terminated string containing "324". Ensure that your function checks for 
        // appropriate boundary conditions and edge cases. Assume you cannot use any standard 
        // libraries (for example, no itoa or sprintf).
       
        // Convert an int to alpha-numeric string 
        // let me think about module function:
        // 324 % 10 = 4, 
        // 324 / 10 = 32
        // go to next iteration        
        public static char[] convertToString(int n)
        {
            // base case 
            if (n == 0)
            {
                return new char[] { '0' };
            }

            bool isNegative = n < 0;
            var number = Math.Abs(n); 

            var rightMostDigit = number % 10;
            var nextIteration  = number / 10;
            bool hasNext = nextIteration > 0;

            var current = (char)('0' + rightMostDigit);
            if (!hasNext)
            {                
                if (isNegative)
                {                    
                    return new char[]{'-', current};
                }

                return new char[]{ current }; 
            }
            
            var result = convertToString(nextIteration);
            var converted = new char[result.Length + (isNegative? 2 : 1)];

            int start = 0;
            if (isNegative)
            {
                converted[0] = '-';
                start = 1; 
            }

            for (int i = 0; i < result.Length; i++)
            {
                converted[start + i] = result[i];
            }

            converted[start + result.Length] = current; // reversed order 

            return converted;             
        }
    }
}