ArrayList vs Arrays - Performance

[Guest]

I wish to build up a byte array from various sources of different lengths. I
can either use a byte array and redimension it as needed as I add the various
values or use an arraylist which automatically expands as required then
convert it to an array after I finish adding the elements. Does anyone know
which would be faster considering that I would probably have about 10 redim
statements if I use a byte array. Microsoft's literature suggests using an
arraylist would be better but I don't always trust M'soft.

 

[Mattias Sjögren]

Dennis,

Does anyone know
which would be faster considering that I would probably have about 10 redim
statements if I use a byte array.

Can't you allocate a byte array that is larger than you initially
need, to reduce the number of ReDims?

I'd avoid ArrayList when working with bytes due to the boxing
overhead.



Mattias

 

[Guest]

What is "boxing overhead"?

Dennis,


Can't you allocate a byte array that is larger than you initially
need, to reduce the number of ReDims?

I'd avoid ArrayList when working with bytes due to the boxing
overhead.



Mattias

 

[Cor Ligthert]

Dennis,

Microsoft's literature suggests using an arraylist would be better
but I don't always trust M'soft.

Why do you have doubts in the case of the arraylist.

It is a list that adds a reference against redimmension a complete array.

When you have doubts about that than you would start in my opinion as well
checking if a multiply operator is faster than a repeated add.

Just my thought,

Cor

 

[Herfried K. Wagner [MVP]]

What is "boxing overhead"?

<URL:http://msdn.microsoft.com/library/en-us/csref/html/vclrfboxingconversionpg.asp>

 

[Guest]

Obviously someone disagrees with you, i.e., post from mattias.