Quickly filling up excel cells from a Array - vba

Question

I generate arrays from a external data tool and now want to fill the cells up using the data in the arrays. I have written the following code.
With ThisWorkbook.Worksheets("Data")
Lastrow = .Cells(.Rows.count, 2).End(xlUp).Row
For i = LBound(Price) To UBound(Price)
.Cells((Lastrow + 1), 1) = Price(i)
.Cells((Lastrow + 1), 2) = Quantity(i)
Lastrow = Lastrow + 1
Next i
End With
All the arrays are of same length and I have around 25 odd arrays to work with. The code works fine but the problem I am facing is of speed. It takes me around 5-6 hours to fill the sheet once with around 3000 as the length of array. Please suggest your best way. Thank you.

Answer 1

Here is an example of how to populate to a range from an array without looping:
Sub PopulateFromArray()
Dim MyArr As Variant
MyArr = Array("Hello", "World", "This is some", "Text")
Range("A1").Resize(UBound(MyArr) + 1, 1).Formula = Application.Transpose(MyArr)
End Sub
We are using resize to resize the range to populate using the upper boundary of the array. We add one to it because it is option base 0. We transpose the array because by the nature of an array the data goes across and we need it to go down. If we wanted to span columns instead of rows we would need to double transpose it like this:
Application.Transpose(Application.Transpose(MyArr))

Answer 2

With ThisWorkbook.Worksheets("Data")
NextRow = .Cells(.Rows.count, 2).End(xlUp).Row + 1
num = UBound(Price) - LBound(Price)
.Range(.Cells(NextRow, 1), .Cells(NextRow + num, 1)) = Application.Transpose(Price)
.Range(.Cells(NextRow, 2), .Cells(NextRow + num, 2)) = Application.Transpose(Quantity)
End With

Answer 3

you can dump an array to a worksheet range very simply like this:
range("A1:B5").value = myArray
you can populate an array conversly:
dim myArray as variant
myArray = range("A1:B5").value
I use this method very frequently, I hardly ever work with data on a worksheet, I prefer to take it into an array first then work with the array.

Answer 4

You have number of arrays (25) with different data (e.g. Price, Quantity, SomeOtherArray) as per your question. As per my comment above.
Option Explicit
Public Sub GetData()
Dim ws As Worksheet
Dim LastRow As Long
Dim arrPrice As Variant
Dim arrQty As Variant
Set ws = Sheets(3)
'-- starts at zero index
arrPrice = Array(50, 60, 70, 75)
arrQty = Array(250, 100, 50, 200)
'-- change columns as per your needs
LastRow = ws.Range("B" & ws.Rows.Count).End(xlUp).Row
'-- UBound + 1 is because the array starts at zero index above
ws.Range("B1").Offset(LastRow).Resize(UBound(arrPrice)+1).Value = Application.Transpose(arrPrice)
ws.Range("B1").Offset(LastRow, 1).Resize(UBound(arrQty)+1).Value = Application.Transpose(arrQty)
End Sub

Answer 5

To fill a range of N rows by M columns, put the data into a 2-dimensional array of the same size, then assign that array to the Value property of the range.
ReDim varValues(1 To lngRowCount, 1 To lngColCount)
Or
ReDim varValues(0 To lngRowCount - 1, 0 To lngColCount - 1)
I presume you can handle populating the array. Then:
Set rngTheRange = 'I presume you can handle this, too
rngTheRange.Value = varValues
Here is an example that uses this technique to fill the current selection with values 0 through N - 1, where N is the number of cells in the selection:
Option Explicit
Public Sub X()
Dim rngCurrent As Range
Dim lngRows As Long
Dim lngCols As Long
Dim lngR As Long
Dim lngC As Long
Dim varValues() As Variant
Set rngCurrent = Selection
lngRows = rngCurrent.Rows.Count
lngCols = rngCurrent.Columns.Count
ReDim varValues(0 To lngRows - 1, 0 To lngCols - 1) As Variant
For lngR = 0 To lngRows - 1
For lngC = 0 To lngCols - 1
varValues(lngR, lngC) = lngR * lngCols + lngC
Next
Next
rngCurrent.Value = varValues
End Sub