Remove Duplicate Characters from a string using array

    class Program

    {

        static void Main(string[] args)

        {

            char[] ch = new char[30];

            string str;

            int count = 1, i, j;

            Console.WriteLine("Enter the string ");

            str = Console.ReadLine();

            int length = str.Length;

            for (i = 0; i < length; i++)

            {

                ch[i] = str[i];

            }

            for (i = 1; i < length; i++)

            {

                for (j = 0; j < i; j++)

                {

                    if (ch[i] == ch[j])

                        break;

                }

                if (j == i)

                {

                    ch[count] = ch[i];

                    count++;

                }

            }

            Console.WriteLine("After removing the duplicat character");

            {

                for (i = 0; i < count; i++)

                {

                    Console.Write(ch[i]);

                }

            }

            Console.WriteLine();

            Console.ReadLine();

        }

    }

OUTPUT: