C# string comma separated to integer array

this C# function will convert an comma separated string in to an array of integers

private int[] commaStrToArray(string strIntComma)
{
string [] strArray;
strArray = strIntComma.Split(new char[] {','});
int [] intArray = new int [strArray.Length];
for (int i = 0; i < strArray.Length; i++)
intArray[i] = int.Parse(strArray[i]);
return intArray;
}

Convert integer array to string comma separated

this is the way to revert the code above
(convert a int array into a string of comma separeted

        private string arrayToCommaStr(int[] intArray)
        {
            string comma = "";
            string strOut = "";

            foreach (int i in intArray)
            {
                strOut += comma + i.ToString();
                comma = ",";
            }
            return strOut;
        }