How can I add looping per 250 cells and offset the array? - excel

Question

I have this code that looks at column A and loops through to create an array to paste to another destination, but I want to manipulate it to loop through sets of 250 cells and create a concatenated array and print it to cells B1. After that set of 250, I go cells a251-a501, and so forth until I reach the end of the list and have each set of 250 concatenated ID's (separated by a ";") to print to the next destination row (B1>B2>B3, etc..)
Sub JC_Fill()
Dim varArray() As Variant
Dim x As Long, i As Long
i = 0
x = 1
With ThisWorkbook.Worksheets("Sheet1").UsedRange.Rows.Count
ReDim varArray(1) 'resize array
Do Until Cells(x, 1).Value = ""
If Cells(x, 1) <> "" Then
varArray(i) = Cells(x, 1).Value
i = i + 1
ReDim Preserve varArray(i)
End If
x = x + 1
Loop
ReDim Preserve varArray(i - 1)
End With
ThisWorkbook.Worksheets("Sheet1").Range("B1").Value = varArray
End Sub
How could I edit my Do While/Loop to repeat the process every 250 cells and then concatenate the array to one cell separated by ; and then offset the next batch until I have no more ID's to cycle through?

Answer 1

Try changing your code this way:
Sub JC_Fill()
Dim OutString
Dim x As Long, i As Long
Dim out_row As Long
i = 0
x = 1
out_row = 1
With ThisWorkbook.Worksheets("Sheet1").UsedRange.Rows.Count
OutString = ""
Do Until Cells(x, 1).Value = ""
If Cells(x, 1) <> "" Then
If (x > 1) Then OutString = OutString & ";"
OutString = OutString & Cells(x, 1).Value
End If
If (x Mod 250) = 0 Then
ThisWorkbook.Worksheets("Sheet1").Range("B" & out_row).Value = OutString
OutString = ""
out_row = out_row + 1
End If
x = x + 1
Loop
End With
ThisWorkbook.Worksheets("Sheet1").Range("B" & out_row).Value = OutString
End Sub

Answer 2

For interest, you can do this without looping each of the 250 cells.
Sub x()
Dim n As Long, v As Variant, r As Range, n2 As Long
n = 5 '250 for you
n2 = Range("A" & Rows.Count).End(xlUp).Row
Set r = Range("A1").Resize(n)
Do While Len(r(1)) > 0
If n2 - r(1).Row < n Then Set r = r.Resize(n2 - r(1).Row + 1)
If r.Count = 1 Then
v = r.Value
Else
v = Join(Application.Transpose(r), ";")
End If
Range("B" & Rows.Count).End(xlUp)(2).Value = v
Set r = r.Offset(n)
Loop
End Sub