How to assign a new value from Method's Array to the Variable?

Question

My main goal is to create a Method, where it is possible to enter a number, out of which a Method will choose some other numbers (according to the purpose) and combine them in Array.

I need this Array and its value to be flexible, so I decided to create a new variable, that is within the scope for both Container() and Main() methods. Then I assigned a value from Container() to optainer, but it didn't work (foreach doesn't display all numbers from Container(), only the first one). Where is my problem?

        static int[] optainer;

        static void Container()
        {
            uint numb = uint.Parse(Console.ReadLine());
            for (int i = 1000000; i >= 1; i--)
            {
                if (numb % i == 0)
                {
                    optainer = new int[] { i };
                }

            }
        }

        static void Main(string[] args)
        {
            Console.WriteLine("Enter num. from 1 to 1 000 000");
            Container();
            foreach (int iw in optainer)
            {
                Console.WriteLine(iw);
            }

            // Expected: few numbers according to the condition; Real result: 1 
        
    ```

Not an answer to your question, but a suggestion: Rather than `for (int i = 1000000; i >= 1; i--)`, you could do `for (int i = Math.Min(1000000, numb); i >= 1; i--)`. If `numb == 6`, it seems unnecessary to do the calculation for any `i > 6`. :) — Astrid E., Apr 26 '22 at 16:09

score 1 · Accepted Answer · answered Apr 26 '22 at 13:54

You have always only one element in optainer, this line is the error optainer = new int[] { i }; you create always a new array with only one item and the last is always 1.

you can change in this way

static List<int> optainer = new List<int>();

        static void Main(string[] args)
        {
            Console.WriteLine("Enter num. from 1 to 1 000 000");
            Container();
            foreach (int iw in optainer)
            {
                Console.WriteLine(iw);
            }
        }

        static void Container()
        {
            uint numb = uint.Parse(Console.ReadLine());
            for (int i = 1000000; i >= 1; i--)
            {
                if (numb % i == 0)
                {
                    optainer.Add(i);
                }

            }
        }

Haven't heard about Lists yet, this solved my problem. Thank you! — Roman Vivtovych, Apr 28 '22 at 12:23

score 0 · Answer 2 · answered Apr 26 '22 at 13:59

0

I'm sure there's a sexier way to do this, but try this:

static void Container()
{
    uint numb = uint.Parse(Console.ReadLine());
    for (int i = 1000000; i >= 1; i--)
    {
        if (numb % i == 0)
        {
            int size = optainer.Length + 1;
            Array.Resize(ref optainer, size);
            optainer[size - 1] = i;
        }
    }
}

answered Apr 26 '22 at 13:59

BashfulCoder

152
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7

Thank's. Actually, I think that using List in this situation is better. – Roman Vivtovych Apr 28 '22 at 12:25
Like I said, I was sure there was a sexier way. Glad you got an answer. – BashfulCoder Apr 29 '22 at 14:39

score 0 · Answer 3 · answered Apr 26 '22 at 14:12

Everytime you write

optainer = new int[] { i };

you create a new list(you overwrite the old one) you would have to append to the array. Therefore you would need to know the size of the array. To save memory you should use something more dynamic like lists.

Here is an explanation how to add a value: Adding values to a C# array

How to assign a new value from Method's Array to the Variable?

3 Answers3