Why my List saves only last element and last occurance?

April 27, 2022

So I have a code here:

string word = "abba";
Counter(word);
public static List<Occur> Counter(string word)
{
    Occur Oc = new Occur();
    var ListNubmersOfWord = new List<Occur>();
    foreach (char c in word)
    {
        Oc.Letter = c;
        Oc.Number = word.Where(x => x == c).Count();
        ListNubmersOfWord.Add(Oc);
    }
    foreach(Occur item in ListNubmersOfWord)
    {
        Console.WriteLine(string.Join(" ", $"{item.Letter} {item.Number}"));
    }

    return ListNubmersOfWord;
}

Here is Occur Class:

public class Occur
{
    public int Number { get; set; }
    public char Letter { get; set; }
}

And the problem is that for some reason list "ListNubmersOfWord" only saves last letter and last occurrence. The outcome is : Any ideas?

>Solution :

In each iteration of the loop, you are setting Letter and Number to the same object reference. Try to instantiate new object inside the body of the foreach loop:

foreach (char c in word)
{
    Occur Oc = new Occur
    {
        Letter = c,
        Number = word.Where(x => x == c).Count()
    };
   
    ListNubmersOfWord.Add(Oc);
}