Check for duplicates sum - excel

Question

I want to check for duplicates in a column and my code is able to do so. But when it finds a duplicate in column L i want it to add "+1" to the integer in column c. So if "L5 and L6" are the same, I want "C5" to be "C5+1". But I have not been able to figure out how to do so.
Sub check_duplicates()
Dim x As Long
Dim LastRow As Long
LastRow = Range("L65536").End(xlUp).Row
For x = LastRow To 1 Step -1
If Application.WorksheetFunction.CountIf(Range("L2:L" & x), Range("L" & x).Value) > 1 Then
Range("C" & x).Formula = "=LEFT(x) + 1"
End If
Next x
End Sub

Answer 1

That should solve your problem:
Sub check_duplicates()
Dim x As Long
Dim LastRow As Long
LastRow = Range("L65536").End(xlUp).Row
For x = LastRow To 1 Step -1
If Application.WorksheetFunction.CountIf(Range("L2:L" & x), Range("L" & x).Value) > 1 Then
Range("C" & x) = Left(Range("C" & x), 1) + 1 & Mid(Range("C" & x), 2)
End If
Next x
End Sub

Answer 2

Replace Range("C" & x).Formula = "=LEFT(x) + 1" with something like Range("C" & x)=Range("C" & x) + 1. Making the formula in C5=C5+1 would be circular and would cause an error. Alternatively, set a variable equal to range C5, add 1 to it, then set range C5 to this variable. I'm assuming column C is a set of integers here and not formulas.

Answer 3

You can increment the value by wrapping the Left function (VBA version) around the cell value to get the value to increment by one and then use the space to extract the value to the right `"P" in your example, then bring them back together.
See the code below. It will work for instances where the number increments above single digits and it also assumes there will always be a space after the number and before the text.
Sub check_duplicates()
Dim x As Long
Dim LastRow As Long
LastRow = Range("L65536").End(xlUp).Row
For x = LastRow To 1 Step -1
If Application.WorksheetFunction.CountIf(Range("L2:L" & x), Range("L" & x).Value) > 1 Then
Dim y As Long, x As String
'increment left number by 1
y = Left(Range("C" & x).Value, InStr(1, Range("C" & x).Value, " ") - 1) + 1
'extract text after space
x = Mid(Range("C" & x).Value, InStr(1, Range("C" & x).Value, " "))
Range("C" & x).Value = y & x ' bring together and set the cell value to new incremented value
End If
Next x
End Sub