Efficiently import multiple spreadsheets into one master sheet using Excel VBA - vba

Question

I am new to VBA and I have some code which I have written and although it works I think it is bulky and not very good should a change ever need to be made to it.
The code opens a spreadsheet, runs a Function (Called "LastRow") to copy the data and another (Called "NxtRow")to paste it into the next empty row of the spreadsheet with the macro then closes the sheet that the data was copied from and moves on to the next one. Basically it is concatenating multiple sheets into one.
I am thinking that there must be a way to write the code to call the functions once and then loop through each sheet in a list. Is this possible?
My code is:
NxtRow() Function
Public Function NxtRow()
Dim BlankRow As Long
Windows("GA_BudgetTool_MASTER.xlsm").Activate
BlankRow = Range("A" & Rows.Count).End(xlUp).Row + 1
Cells(BlankRow, 1).Select
ActiveSheet.Paste
BlankRow = Range("A" & Rows.Count).End(xlUp).Row + 1
Cells(BlankRow, 1).Select
End Function
LstRow() Function
Public Function LastRow()
Dim LstRow As Long, LstCol As Long, Rng As Range, A3 As Range
LstRow = Range("A" & Rows.Count).End(xlUp).Row
LstCol = Range("O" & LstRow).Column
Set Rng = Range(Cells(LstRow, 1), Cells(LstRow, LstCol))
Set A3 = Range("A3")
Range(A3, Rng).Select
Selection.Copy
End Function
VBA Sub()
Sub ImpData()
' Deactivate Screen Updating and Display Alerts
Application.ScreenUpdating = False
Application.DisplayAlerts = False
' Import Worksheet 1
Workbooks.Open Filename:= _
"Worksheet1_Filename.xlsx"
LastRow
NxtRow
Windows("Worksheet1.xlsx").Activate
ActiveWindow.Close
' Import Worksheet 2
Workbooks.Open Filename:= _
"Worksheet2_Filename.xlsx"
LastRow
NxtRow
Windows("Worksheet2.xlsx").Activate
ActiveWindow.Close
' Import Worksheet 3
Workbooks.Open Filename:= _
"Worksheet3_Filename.xlsx"
LastRow
NxtRow
Windows("Worksheet3.xlsx").Activate
ActiveWindow.Close
This goes on in this fashion for about 30 sheets. Is there an easier way to write this and make it easier to amend later if needed?

Answer 1

I would just make a little array of your filenames and then use a for loop to repeat the function calls as many times as necessary
Sub ImpData()
'Deactivate Screen Updating and Display Alerts
With Application
.ScreenUpdating = False
.DisplayAlerts = False
End With
Dim filenames As Variant
filenames = Array("file1", "file2")
For i = 1 To UBound(filenames) + 1
Workbooks.Open Filename:=filenames(i - 1)
LastRow
NxtRow
Windows("Worksheet" & i & ".xlsx").Activate
ActiveWindow.Close
Next i
'Reactivate Screen Updating and Display Alerts
With Application
.ScreenUpdating = True
.DisplayAlerts = True
End With
End Sub