using System;

using System.Collections;

public class Program

{

    public static void Main()

    {

        Hashtable ht = new Hashtable();

​

        Component c = new();

​

        Console.WriteLine($"Hash Code of component: {c.GetHashCode()}");

​

        // Add component to collection

        ht.Add(c, "some value");

​

        Console.WriteLine($"Does hashtable contain the component: {(ht.Contains(c) ? "yes" : "no")}");

​

        // Change component's value

        c.value = 42;

​

        Console.WriteLine($"Hash Code of component: {c.GetHashCode()} - exactly the same as previous");

​

        Console.WriteLine($"Does hashtable contain the component: {(ht.Contains(c) ? "yes" : "no - but hash did not change")}");

​

        // Try adding the component again

        ht.Add(c, "other value");

​

        foreach (DictionaryEntry comp in ht)

        {

            Console.WriteLine($"Component with hash {comp.Key.GetHashCode()} and value: {(comp.Key as Component).value}. Hashtable entry value: {comp.Value}");

        }

    }

}

​

public class Component

{

    public static int idProvider = 31173;

    public readonly int id;

    public double value = 0;

​

    public Component()

    {

        id = idProvider++;

    }

​

    public override int GetHashCode()

    {

        return id;

    }

​

    public override bool Equals(object obj)

    {

        return obj is Component component && component.id == id;

    }

}

​