How to make an IList of a certain type?

Question

I'm trying to make an IList of the type Vector2. Why doesn't this work..?

 IList<Vector2> borderPixels;

Do I have to import something?

Answer 1

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Answer by willparsons · Sep 09, 2015 at 08:18 AM

Make you class inherit from System.Collections.Generic and change the datatype from IList to just List.

 List<Vector2> borderPixels = new List<Vector2>();

That should do the trick.

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Answer 2

Answer by FortisVenaliter · Sep 08, 2015 at 07:52 PM

Because IList is an interface, not a class. Look up the interface keyword and abstraction/inheritance for more information, but you can never instantiate an abstract class or interface. You're probably looking for the List class instead.

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Bunny83 · Sep 08, 2015 at 09:56 PM 1

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Right.
So you can have your variable be declared as IList<Vector2> but you need an actual class instance. So you can do this:

 IList<Vector2> borderPixels = new List<Vector2>();

The List<T> class implements the IList<T> interface so you can assign a List<T> instance to a IList<T> variable. However you could use any other class that implements the IList<T> interface. Using the IList interface usually only makes sense if you write some framework / abstraction yourself where your class doesn't need to know the actual implementation. It just needs "some kind" of "list".

In most cases you would use directly the type List<T>

 List<Vector2> borderPixels = new List<Vector2>();

How to make an IList of a certain type?

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