C#•16mo ago

❔ Trying to write to file of a Collatz Conjecture program

hello, complete beginner here. im trying to make a program that takes a random number and puts it through the collatz conjecture, then sends every number used in the collatz conjecture to a .txt file on a USB drive. (quite a mouthful, i know). ive got the part about the collatz conjecture done, but i cant write to a file; i tried using streamwrite and File.WriteAllLines with an array

        static void Main(string[] args)
        {
            Random randgen = new Random();
            UnicodeEncoding encoder = new UnicodeEncoding();

            Console.ReadLine();

        start:

            var values = Array.Empty<string>();

            int selectedNum = randgen.Next();
            int x = selectedNum;

            string localPath = (@"D:\COLLATZ\" + Convert.ToString(x) + ".txt");

            Console.WriteLine("Input: {0}", selectedNum);
                
                while (x > 0)
                {
                    if (x == 1)
                    {
                        break;
                    }
                    if (x % 2 == 0)
                    {
                        x = x / 2;
                        Console.WriteLine("{0} | {1} | {2}", x, "div", Convert.ToString(x % 2));

                    }
                    else
                    {
                        x = (x * 3) + 1;
                        Console.WriteLine("{0} | {1} | {2}", x, "mul", Convert.ToString(x % 2));
                    }

                values.Append(Convert.ToString(x));

            }

            File.WriteAllLines(localPath,values);

            Console.WriteLine(String.Join(",", values));
            Console.ReadKey();

            goto start;
        }
    }
}

        static void Main(string[] args)
        {
            Random randgen = new Random();
            UnicodeEncoding encoder = new UnicodeEncoding();

            Console.ReadLine();

        start:

            var values = Array.Empty<string>();

            int selectedNum = randgen.Next();
            int x = selectedNum;

            string localPath = (@"D:\COLLATZ\" + Convert.ToString(x) + ".txt");

            Console.WriteLine("Input: {0}", selectedNum);
                
                while (x > 0)
                {
                    if (x == 1)
                    {
                        break;
                    }
                    if (x % 2 == 0)
                    {
                        x = x / 2;
                        Console.WriteLine("{0} | {1} | {2}", x, "div", Convert.ToString(x % 2));

                    }
                    else
                    {
                        x = (x * 3) + 1;
                        Console.WriteLine("{0} | {1} | {2}", x, "mul", Convert.ToString(x % 2));
                    }

                values.Append(Convert.ToString(x));

            }

            File.WriteAllLines(localPath,values);

            Console.WriteLine(String.Join(",", values));
            Console.ReadKey();

            goto start;
        }
    }
}

3 Replies

reflectronic•16mo ago

values.Append(Convert.ToString(x)); does not do what you think it does it does nothing, actually, in this instance it returns a new list, it doesn't change values i think you want values to be a List<string>:

var values = new List<string>();

var values = new List<string>();

and then you want to call Add on values:

values.Add(x.ToString());

values.Add(x.ToString());

in C#, an array cannot be "appended" to, it has a fixed size. you use List<T> instead

katze•16mo ago

thanks!

Accord•16mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Trying to write to file of a Collatz Conjecture program