Empty an array

[jedidja]

Hello,

I'm looking for a way to empty a global variable, declared as an array of a user-defined type, and this several times in the program

Example:

Type BSCSCustomer
customer_id As Long
MatchCustomerNumber As Integer
MatchInvoice As Integer
MatchExternalReference As Integer
MatchGSMNumber As Integer
MatchAccountNumber As Integer
MatchName As Integer
MatchAddress As Integer
End Type

Global PossibleCust (0 To 200) As BSCSCustomer

I already tried REDIM PRESERVE, but I get the compile error 'Array already Dimensioned'. The goal is to be sure that the variable is empty before I re-use it.

Thanks!!

[James Stanich]

Erase ARRAYNAME

[jedidja]

I tried it but it works only on procedure level.
It concerns a global variable used in whole the program.

[Frans C]

You can only erase a dynamic array.

When the array is declared as:
Global PossibleCust (0 To 200) As BSCSCustomer

Erase PossibleCust ' will produce an error

But when the array is declared like this:

Global PossibleCust () As BSCSCustomer
ReDim PossibleCust(0 to 200)

You can erase the array

Erase PossibleCust ' will produce no error anymore

[jedidja]

Works perfectly, Thanks!

[James Stanich]

Originally posted by Frans C
You can only erase a dynamic array.

When the array is declared as:
Global PossibleCust (0 To 200) As BSCSCustomer

Erase PossibleCust ' will produce an error

But when the array is declared like this:

Global PossibleCust () As BSCSCustomer
ReDim PossibleCust(0 to 200)

You can erase the array

Erase PossibleCust ' will produce no error anymore

Damn, learn something new everyday...

[Frans C]

I have to correct myself (sorry James, you were correct )

You can erase a fixed dimensioned array, but it doesn't have the same effect as erasing a dynamic array. Erase reinitializes the elements of fixed-size arrays and releases dynamic-array storage space.

When the array is declared as:
Global PossibleCust (0 To 200) As BSCSCustomer

Erase PossibleCust

This will reset all elements to the defaults for it's variabletype (integers to 0, strings to "" etc.) , but the array is still dimensioned from 0 to 200

But when the array is declared like this:

Global PossibleCust () As BSCSCustomer
ReDim PossibleCust(0 to 200)

Erase PossibleCust

Now the array is completely empty, you have to redimension it before you can use it.


Damn, learn something new everyday...

[James Stanich]

sorry James, you were correct

Woo-hoo. That always nice to hear, but at least you figured it out...

[sgrya1]

What am I doing wrong?
I have a bunch of arrays that are all declared as

global xx(9) as single

Why is it that when I erase them using

erase xx()

Most of the arrays are emptied, which is what I want.
But a few are erased to return values of zero which is not what I want.

I don't see why they are being treated differently.

[bushmobile]

well, erasing a fixed dimension array shouldn't empty it (i.e. remove all the members) only reset the values to their default.

without more code it's hard to say what's going on.

[Merri]

String arrays go fully empty, but with numeric datatype arrays the values are made zero. This is actually what happens to string arrays as well, but with strings zeros are treated as null strings. By default the actual string array value for an item is a pointer to the actual string data in memory. You just can't see this directly in VB6.

If you are to handle numeric data, then you should retain the numeric datatype you use. If you use numbers as strings, you'll get unexpected problems in some cases.

[sgrya1]

Attached is a very simple vb project which highlights my problem. Can someone please explain why the two variables get treated differently and how I can get them all to operate in the same way.

Hope it's not just the version of VB6.0 that I'm using.
One variable gets emptied while the other sets to 0.
Wierd thing is that when I remove all the other arrays and just leave the two then they both get set to 0.

[[Pieter]]

It has to do with the way you declared the arrays. Some arrays you specify with a type, others not. The correct way to do it is:

Global LeftY1_(9) As Single, LeftY2_(9) As Single, ..., BottomX2_(9) As Single

instead of

Global LeftY1_(9), LeftY2_(9) , ..., BottomX2_(9) As Single

Only BottomX2_ is of the type Single.

Pieter

[sgrya1]

That's been killing me. Thankyou.
I take it that the array defaults to string because you can empty it?
Don't know what As Single is yet anyway.

[gavio]

Single (number) - single precision floating point, 4 bytes