VBA Macro Run time error 6: overflow- coding inside a loop

Question

Having a problem with this Error. I am creating a GA and the loop is to assign my fitness value to an array.

some of the variables

Dim Chromolength as integer
Chromolength = varchromolength * aVariables 
Dim i as integer, j as integer, counter as integer
Dim Poparr() As Integer
Dim FitValarr() As Integer

the code:

ReDim Poparr(1 To PopSize, 1 To Chromolength)

For i = 1 To PopSize                
  For j = 1 To Chromolength       
    If Rnd < 0.5 Then           
        Poparr(i, j) = 0
    Else
        Poparr(i, j) = 1        
    End If
  Next j
Next i

For i = 1 To PopSize                   
 j = 1                           
 counter = Chromolength              
 Do While counter > 0  
   FitValarr(i) = FitValarr(i) + Poparr(i, counter) * 2 ^ (j - 1)          
  j = j + 1                   
  counter = counter - 1       
 Loop
Next i      

I am having problems with:

FitValarr(i) = FitValarr(i) + Poparr(i, counter) * 2 ^ (j - 1) 

I apologize, I am fairly new to VBA.

Answer 1

An overflow condition arises when you create an integer expression that evaluates to a value larger than can be expressed in a 16-bit signed integer. Given the expression, either the contents of FitValarr(i), or the expression 2^(j-1) could be overflowing. Suggest all the the variables presently declared as Int be changed to Long. Long integers are 32-bit signed values and provide a correspondingly larger range of possible values.