Make the number of nested for loops a variable - VBA - vba

Question

I have developed a code like this
For i = 1 To 50
For j = i + 1 To 50
For k = j + 1 To 50
..........................
'Here I have someother code
..........................
Next k
Next j
Next i
So this is a nested for loop. And there are 3 for loops in this code.
Now what I want is, I want to make the number of for loops a variable. For an example I have variable call NumberOfForLoops. So if NumberOfForLoops=3 then there should be 3 for loops. If NumberOfForLoops=8 then there should be 8 for loops. I can't find how to do this.
I think it is better to explain what I was trying to accomplish.
I'm trying to find possible combinations
For 3 combinations I wrote this code
Dim WS_Data As Worksheet
Dim WS_Result As Worksheet
Set WS_Data = Worksheets("Data")
Set WS_Result = Worksheets("Result")
Dim i As Long
Dim j As Long
Dim k As Long
Dim EnteringRow As Long
EnteringRow = 1
For i = 1 To 5
For j = i + 1 To 5
For k = j + 1 To 5
WS_Result.Range("A" & EnteringRow).Value = WS_Data.Range("A" & i).Value
WS_Result.Range("B" & EnteringRow).Value = WS_Data.Range("A" & j).Value
WS_Result.Range("C" & EnteringRow).Value = WS_Data.Range("A" & k).Value
EnteringRow = EnteringRow + 1
Next k
Next j
Next i
It gave me below result
Input and Outcome
But now what I need is I want to make the number of items I select from the list dynamic. According to the anwers I understood that I need to use a recursion concept.
So I modified the code according to h2so4's answer.
This is the modified code
Sub test()
Dim WS_Data As Worksheet
Dim WS_Result As Worksheet
Dim WS_Temp As Worksheet
Set WS_Data = Worksheets("Data")
Set WS_Result = Worksheets("Result")
Set WS_Temp = Worksheets("Temp")
ResultRow = 1
NofL = 3
Nestedloop WS_Data, WS_Result, WS_Temp, ResultRow, NofL, 1, 5, 1
End Sub
Sub Nestedloop(WS_Data, WS_Result, WS_Temp, ResultRow, NofL, jmin, jmax, level)
For j = jmin To jmax
WS_Temp.Cells(1, level) = j
'your code when a value of j is set
If level < NofL Then
Nestedloop WS_Data, WS_Result, WS_Temp, ResultRow, NofL, jmin + 1, jmax, level + 1
Else
'your code when the number of loops is reached
For i = 1 To NofL
WS_Result.Cells(ResultRow, 0 + i).Value = WS_Data.Range("A" & WS_Temp.Cells(1, i).Value).Value
Next i
ResultRow = ResultRow + 1
End If
Next j
End Sub
I used a tempory sheet. This is the result I got.
Result got
Difficult to understand what is wrong.

Answer 1

another proposal with recursive sub that simulates nested loops
Sub test()
NofL = 4
Nestedloop NofL, 1, 50, 1
End Sub
Sub Nestedloop(NofL, jmin, jmax, level)
For j = jmin To jmax
Cells(1, level) = j
'your code when a value of j is set
If level < NofL Then
Nestedloop NofL, jmin + 1, jmax, level + 1
Else
'your code when the number of loops is reached
End If
Next j
End Sub

Answer 2

Your question can be read in more than one way. If you are looking for a tool to help in generating boiler-plate code, perhaps something like this:
'In the following code, if vars is missing, successive loop indices are "i", "j", "k", etc
'otherwise, vars is treated as the loop vars and should be passed as a 0-based array with
'depth strings, where depth is how deeply nested the loops are
Function NestedFors(lim As Long, depth As Long, Optional vars As Variant) As String
Dim i As Long, n As Long
Dim codeShell As String
If IsMissing(vars) Then
vars = Split("i j k l m n o p q r s t u v w x y z") 'should be overkill -- if not, you deserve a runtime error!
End If
codeShell = "For " & vars(0) & " = 1 To " & lim & vbCrLf
For i = 1 To depth - 1
codeShell = codeShell & String(i, vbTab)
codeShell = codeShell & "For " & vars(i) & " = " & vars(i - 1) & " + 1 To " & lim & vbCrLf
Next i
codeShell = codeShell & String(depth, vbTab) & "'----- Insert code here ------" & vbCrLf
For i = depth - 1 To 1 Step -1
codeShell = codeShell & String(i, vbTab) & "Next " & vars(i) & vbCrLf
Next i
codeShell = codeShell & "Next " & vars(0) & vbCrLf
NestedFors = codeShell
End Function
Then, for example if you type
?nestedfors(50,4)
in the Immediate Window you get the following (which can be copy-pasted to a code window above:
For i = 1 To 50
For j = i + 1 To 50
For k = j + 1 To 50
For l = k + 1 To 50
'----- Insert code here ------
Next l
Next k
Next j
Next i

Answer 3

edited to produce nested loops
Option Explicit
Sub main()
Dim NumberOfForLoops As Long
NumberOfForLoops = 3
ForLoops NumberOfForLoops, 1, 50
End Sub
Sub ForLoops(nLoops As Long, jMin As Long, jMax As Long, Optional level As Long)
Dim j As Long
If level = 0 Then level = 1
For j = jMin To jMax
If level < nLoops Then
ForLoops nLoops, jMin + 1, jMax, level + 1
Else
'your "someother" code
End If
Next j
End Sub

Answer 4

If you want to run the first nested loop "NumberOfForLoops" times, just change the "To" part to NumberOfForLoops.
For i = 1 To 50
For j = 1 To NumberOfForLoops
For k = j + 1 To 50
..........................
'Here I have someother code
..........................
Next k
Next j
Next i