Arrays - Clearing and Testing

[buck1107]

Hi,
I'm currently working with an Classic ASP page (VB Script) that utilizes the same array at several points during the page. After each use, I erase the array. The problem is, what is the best way to detect if the array is empty through an if/then statement?

Here's how I've been erasing the arrays:

If IsArray(a) Then
Erase a
End If

In the outer If/Then statement, I test for

IsArray(array)

The array that had been erased still exists.

On the inner If/Then statment, I'd been using

Not IsEmpty(array)

as well as

UBound(array)<>-1

although I would get an error message when using the latter (out of range), while in the former, an erased array would show as "true" (not empty). In the meantime, I've created flags as a workaround, but it's not the ideal situation. Any help or resources would be greatly appreciated.

Thanks!

[Demaestro]

not sure of the syntax but I can offer you a logic change.

Instead of erasing the array you should set it to an empty array, then instead of checking if it exists.... check to see if it's length is > zero

[buck1107]

Thanks,
From what I've read, it seems that the Erase method clears the array. Would the ReDim method be preferrable in this case?

Also, in determining if the array is greater than 0, I can't use UBound. Do the following look correct? I'm not familiar with "Is Nothing". When I added it, I got the "object required" message.

If Not(IsNull(vArray(a))) And Not(IsEmpty(vArray(a))) And Not(a) Is Nothing) 

Thanks again!

[Demaestro]

buck,

My asp is about 9 years rusty so I am not in a position to advise on what would be preferable.

I did a little looking and it appears that erase is a correct method, I don't know if it is the best way to go about it.

Curious why you can't use Ubound?

[buck1107]

Thanks
When I use this:

If (UBound(arrCompareItem1_js)<>-1) Then

It results in:
"Subscript out of range: UBound"

[Demaestro]

try

If (UBound(a) > 0) Then

[buck1107]

Thanks!

I found that

ReDim a(-1)

did the trick

That clears the array by setting its upper bound to -1.