C# ArrayList

John Arcadella

I am building a very complex application that deals with arrays of number, strings, objects and names. I see there are many ways to do this such as I can build manual arrays

Working with Arrays in C# .NET

OR I can use Array class or I can use ArrayList class.

C# ArrayList

Question is, which is the fastest way?

Thank you for your expert advice!

2 Replies

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Vulpes15y ago
Accepted answer
The fastest collection is the single dimensional array of type T.

This is closely followed by List if you need dynamic resizing capability.

If T is a value type (such as int, double etc) List is significantly faster than an ArrayList which stores everything as objects on the heap. This requires that the value types are boxed and then unboxed (using a cast) when they need to be retrieved, which is a slow operation.

If T is a reference type, there's no appreciable difference in speed between List and ArrayList though the former is easier to use as it's strongly typed and casting is never required.
Suthish Nair15y ago
You can use Generic Collections.