Question

Is there a reason to stick to Arrays as the default list data structure in AS3 if you are targeting Flash Player 10? Why not use Vectors (typed arrays) as default throughout your program since they are:

• faster
• type checked

Does it perform badly or incur higher memory overheads? Any reason to use arrays anymore?

Answer 1

I’m answering my own question based on what I learnt of the issue.

Vectors are faster for these datatypes ONLY: — (proof)

• int
• uint
• Number
• Boolean

Arrays are preferable for all other types:

• Strings
• classes

Vectors are more limited to work with:

• reading/writing is bounds checked
  • non-existent slots cannot be set directly with [5] = Val
  • non-existent slots cannot be read (or you’ll get an Exception)
• must push() to create slots
• sorting is slower

Vectors are more troublesome:

• multi-D arrays cannot be convert to a vector
• vector cannot be converted to a multi-D array
• cannot work with String.split()
• fixed type for all elements – unusable for JSON

Vectors can be easier to debug:

• setting a [Vector of ints] into a [Vector of Vector of ints] will throw an Exception
• compile time errors (in some cases)
  • when trying to set a [Vector of ints] into a [Vector of Strings]
  • when trying to set a [Vector of ints] into a [Vector of Vector of ints]