Variables in Declaring an Array

  • Thread starter Thread starter Jimmy
  • Start date Start date
J

Jimmy

Dim myArray(0 To n) As String

The dimensions of this array change throughout.

Why can't I use the variable 'n' in the declaration?

And, more importantly, can someone help me solve this problem?

Thanks,

Jimmy
 
Take a look for help on the redim statement (note the key work preserve is
required to not clear the values of the array when it is resized.)

dim myArray() as sting
dim n as long

n = 0
redim preserve myArray(n)
myarray(0) = "this"
n = 1
redim preserve myarray(n)
myarray(0) = "that"
 
2 things jim

you have a typo here:
dim myArray() as sting (string)

and should this be:

array(n) = "that"
 
My typing takes a little to be desired... I should really proof read before
hitting the Post button. You are correct on the String thing. As for the
Array(n) = "that"
it was just a quick n dirty demo. Yes n probably makes more sense...
 
i'm not as knowledgeable as you, i was just checking how it worked so i could
learn more about arrays. noticed how i "asked" instead of saying "this is how it
should be". i didn't know for sure. it should also probably be:
myarray(n) = "this"
right?

i know i don't type very well, so i understand the typo.

thanks
 
Looks like you have the hang of ReDim to me... Like I said in my original
post the only trick is to understanding the use of the preserver key word.
Preserve adds some overhead however so my origninal code should have been...

dim myArray() as sting
dim n as long

n = 0
redim myArray(n) 'Note no Preserve as there is nothing to save
myarray(n) = "this"
n = 1
redim preserve myarray(n)
myarray(n) = "that"

Redim essentially makes a new array that is the size that you specify and
then points the array variable at the new array. The preserve key word tells
the compiler to copy over the values from the old array to the new array...
 
So Jim, are you saying that if Jimmy inserts the lines of code that you have
provided that the can then use "Dim myArray(0 To n) As String and his array
will run properly? Or am I totally confused with this.
 
You are confused a bit... You can not declare a variable with an undefined
attribute. The array must be declared undimensioned. It can then be
dimensioned at run time as I have shown.

dim myArray () as String 'Undimensioned array

redim myArray(100) 'Dimension the array with 101 elements 0 to 100
myArray(0) = "tada" 'add values to the array
 
you can't but you have 2 options.
You can declare const like const MAX_ITEMS AS INTEGER before declaring
variables (see example 1)
Another option is not using a fixed array but a variable size array
(see example 2)
Hope this helps.

example 1
CONST MAX_ITEMS AS INTEGER=10
Dim myArray(0 To MAX_ITEMS ) As String

Example 2
option base 1
dim n as integer
dim myArray() as string
n=15
redim myArray(1 to n)
 
Jim,
How do I populate myArray with Range("C1:C100")?

e.g. I want myArray(0) to equal "C1".value, myArray(1) to equal
"C2".value, (& so on)


btw, This whole conversation has been emensly helpful. keep it up!
Thanks,
Jimmy
 
That was a stupid. Please ignore.

Jim,
How do I populate myArray with Range("C1:C100")?

e.g. I want myArray(0) to equal "C1".value, myArray(1) to equal
"C2".value, (& so on)


btw, This whole conversation has been emensly helpful. keep it up!
Thanks,
Jimmy
Click to expand...
 
Jim,
I'm still on the same project, but our team has decided to use a
two-dim array.
How can I get "redim preserve myarray(n,o)" to work?
I'm having the worst time with this.
Thanks so much,
Jimmy
 
Jimmy said:
Jim,
I'm still on the same project, but our team has decided to use a
two-dim array.
How can I get "redim preserve myarray(n,o)" to work?
I'm having the worst time with this.
Thanks so much,
Jimmy
Click to expand...

A little more info would be helpful. I suspect your difficulty arises
from the fact that the ReDim Preserve structure will allow you to change
only the last dimension of the array. E.g., if the array has been
dimensioned with 2 "rows" and 3 "columns", you can use ReDim Preserve to
change the number of "columns" but not the number of "rows". You might
want to post back with a sample code snippet if that's your difficulty.

Alan Beban
 
Thanks, Alan.
I got a little side tracked on another "%^#@(*&^*($" today.
But when I get back to this one, I'll post more here.

In the mean time, I have another question that I'm about to ask on a
separate posting.

Thanks again,
Jimmy
 
First of all, thanks to all who endeavor to help me with this project:
Here it is:



I want to make a 2dim array.
The current code populates that array at Row15 (see below).
I would like to change this 1dim to a 2dim

The main problem is that I am constantly refrishing the array at either
row33 or row35.

Thank you in advance,
Jimmy


1 ent_ku = Range("B2").Value
2 ent_or= Range("F2").Value
3 currentlastrow = Range("B65536").End(xlUp).Row
4 j = 2
5 pvFlag = False
6 ifMatch = False
7 Range("A1").Select
8
9 For i = Range("B2").Row To currentlastrow Step 1
10 h = i
11 current_Desc = Range("D" & i).Value
12 If Range("B" & i).Value = ent_ku Then
13 ifMatch = True
14 ReDim Preserve myArray(q)
15 myArray(q) = Range("F" & i).Value
16 If Range("F" & i).Value = "PVJco" Then
17 pvFlag = True
18 pvPrice = Range("I" & i).Value
19 pvChgDate = Range("J" & i).Value
20 End If
21
22 q = q + 1
23
24 ElseIf pvFlag = True Then
25 q = 0
26 locust = Application.Min(Range("I" & j, "I" &
(i - 1)))
27 percentAbv = (pvPrice - locust) / locust
28 lowCompet = Application.Min(Range("I" & j, "I" & (i -
1))).Row
29 i = i - 1
30
31 j = i
32 pvFlag = False
33 ReDim myArray(q)

ElseIf pvFlag = False Then
34 q = 0
35 ReDim myArray(q)
36 i = i - 1
37 End If
38
39 ActiveCell.Offset(1, 0).Select
40 ent_ku = Range("B" & h).Value
41
42 Next
 
It would be easier on responders if you were to use a simpler example to
focus on the problem you're trying to solve, a la

Dim arr()
ReDim arr(2,3) 'or whatever
'...whatever
ReDim arr(?,?) 'or whatever

Alan Beban
 
You're right, Alan.
Though, the other half of the time I am directed to make my sample
codes longer and more
detailed. Go Figure.

I think that I figured out a way to do it without trying to use a 2dim
array that must refresh itself. Let's keep our fingers crossed that
this will be the magic bullet that I am looking for.


I apprciate all you help.
Thanks,
Jimmy
 
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