c# When should I use List and when should I use arraylist?

Question

As the title says when should I use List and when should I use ArrayList?

Thanks

Answer 1

The main time to use ArrayList is in .NET 1.1

Other than that, List<T> all the way (for your local T)...

For those (rare) cases where you don't know the type up-front (and can't use generics), even List<object> is more helpful than ArrayList (IMO).

Answer 2

Since List is a generic class, I would tend to always use List.

ArrayList is a .NET 1.x class (still available & valid though), but it is not 'typed'/generic, so you'll need to cast items from 'object' back to the desired type; whereas when using List, you don't have to do that.

Answer 3

You should always use List<TypeOfChoice> (introduced in .NET 2.0 with generics) since it is TypeSafe and faster than ArrayList (no un-necessary boxing/unboxing).

Only case I could think of where an ArrayList could be handy is if you need to interface with old stuff (.NET 1.1) or you need an array of objects of different type and you load up everything as object - but you could do the latter with List<Object> which is generally better.

Answer 4

Use List where ever possible. I can't see any use to ArrayList when high performing List exists.

Answer 5

List is using whenever you want to store Object reference in List. Just Like List. And ArrayList is used whenever you want to store any simple string or no or any basic data.

Answer 6

As other said. You should use the List generic, almost always when you know the type (C# is a strong-typed language), and other ways when u do polymorphic/inhertance classes or other stuff like that.

Answer 7

ArrayList is an older .NET data structure. If you are using .NET 2.0 or above always use List when the array needs to hold items of the same type. Usage of List over ArrayList improves both performance and usability.