Why am I unable to set the size of an array based on a variable? What's the best way around this?
Dim NumberOfZombies as integer
NumberOfZombies = 20000
Dim Zombies(NumberOfZombies) as New Zombie
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5 Answers
You can use a dynamic array when you don't know the number of values it will contain until run-time:
Dim Zombies() As Integer
ReDim Zombies(NumberOfZombies)
Or you could do everything with one statement if you're creating an array that's local to a procedure:
ReDim Zombies(NumberOfZombies) As Integer
Fixed-size arrays require the number of elements contained to be known at compile-time. This is why you can't use a variable to set the size of the array—by definition, the values of a variable are variable and only known at run-time.
You could use a constant if you knew the value of the variable was not going to change:
Const NumberOfZombies = 2000
but there's no way to cast between constants and variables. They have distinctly different meanings.
Comments
You have to use the ReDim statement to dynamically size arrays.
Public Sub Test()
Dim NumberOfZombies As Integer
NumberOfZombies = 20000
Dim Zombies() As New Zombie
ReDim Zombies(NumberOfZombies)
End Sub
This can seem strange when you already know the size of your array, but there you go!
Comments
You can also look into using the Collection Object. This usually works better than an array for custom objects, since it dynamically sizes and has methods for:
- Add
- Count
- Remove
- Item(index)
Plus its normally easier to loop through a collection too since you can use the for...each structure very easily with a collection.
Comments
You need to use a constant.
CONST NumberOfZombies = 20000
Dim Zombies(NumberOfZombies) As Zombies
or if you want to use a variable you have to do it this way:
Dim NumberOfZombies As Integer
NumberOfZombies = 20000
Dim Zombies() As Zombies
ReDim Zombies(NumberOfZombies)
3 Comments
sooprise
Is there a tidier way to cast NumberOfZombies as a CONST right in the dimension definition? Dim Zombies(CONST NumberOfZombies) as new Zombie
carny666
I submitted my answer before I was finished typing.
sooprise
Oh, I see, so a variable can be used to define a dimension if Redim is used, that is helpful to know, thanks!
There is a stupid way to do it XD I am breaking an address into different cell by counting character.
Just show you directly.
q = 1
ReDim Sentence1(q) As String
ReDim Sentence1T(q) As String
Sentence1(q) = Result(0)
For p = 1 To WordCount - 1
Sentence1(q) = Sentence1(q) & " " & Result(p)
If Len(Sentence1(q)) > 40 Then
For r = 1 To q
Sentence1T(r) = Sentence1(r)
Next r
q = q + 1
ReDim Sentence1(q) As String
For r = 1 To q - 1
Sentence1(r) = Sentence1T(r)
Next r
ReDim Sentence1T(q) As String
End If
Next p
So every time you redim it, you lost your data. Just put it in another array. Hope you like it!
