c# create instance and add elements to a collection given a type, which can be: Arrays, Lists, Dictionaries, Queues, Stacks

Question

I have the following code

public void example(Type t)
{
    var collector = (ICollection)Activator.CreateInstance(t);

    Debug.Log(collector);
}

this prints

System.Collections.Generic.List`1[System.Int32]
System.Collections.ArrayList

but I need to add elements

Explaining myself better

I have the type of ICollection, I need to take it to a generic structure that allows me to add or insert elements

public void example(Type t){

   var my_collector = new AnyClass((ICollection)Activator.CreateInstance(t));

   collector.Add(new element());
   //or
   collector.insert(new element(),0);
}

but, I'm not interested in printing the elements, this I did to show the types of collectors that will come. I'm only interested in adding or inserting elements in the new ICollector

Anyway, thanks for your answers

Why don't you iterate over the collection elements and 'log' them one by one? — Aly Elhaddad, Dec 16 '17 at 08:14
Possible duplicate of '[printing all contents of array in C#](https://stackoverflow.com/q/16265247/3602352)' — Aly Elhaddad, Dec 16 '17 at 08:19
It's looks like an XY problem. Could you please describe what is your initial goal? And by the way you can't extend an array. — Aleks Andreev, Dec 16 '17 at 08:22

score 0 · Accepted Answer · answered Dec 16 '17 at 10:26

You can't add elements to an ICollection. You'll need to downcast 'collector' to IList, Queue, or Stack:

switch (collector)
{
    case IList list:
        list.Add("something");
        break;
    case Queue queue:
        queue.Enqueue("something");
        break;
    case Stack stack:
        stack.Push("something");
        break;
}

c# create instance and add elements to a collection given a type, which can be: Arrays, Lists, Dictionaries, Queues, Stacks

1 Answers1