Excel VBA Length-1 In a Range - vba

Question

I recently got into Excel macro development after a long time of not having the need to.
I have one column with two-hundred rows where each row has a value. I wrote a loop to iterate to each row value, read the current value and then write the value back minus the last character.
Here is some actual (and pseudo) code of what I wrote.
Dim theRow as Long
Dim totRow as Long
Dim fooStr as String
theRow = 2 'we begin on the second row of the colummn
totRow = 201 'there are 200 values
For theRow = 2 to totRow
fooStr = WorkSheets(DestSheet).Cells(theRow,"A").Formula 'read the cell value
fooStr = Left(fooStr,Len(fooStr)-1 'subtract the last character from the value
Cells(theRow,1).Value = fooStr 'write the value back
Next theRow
After I did some reading I learned that it is best practice to read and write values using a Range. Is it possible to rewrite what I am doing using a Range so it willl go faster.
Here is what I came up with so far.
Range("A2:A201").Value = Len(Range.Left("A2:A201").Value)-1
However, this doesn't work.
Any clues on how to do this if this is indeed possible?
Thanks for any tips.

Answer 1

If you want maximum performance (you don't need it for 200 rows, but...) you have to minimize the number of reads and writes (mostly writes) to ranges. That means reading the whole range into an array, manipulating the array, then writing it back to the range. That's one read and one write compared to 200 in a loop. Here's an example.
Sub RemoveLastChar()
Dim vaValues As Variant
Dim i As Long
vaValues = Sheet1.Range("A2").Resize(200).Value
For i = LBound(vaValues, 1) To UBound(vaValues, 1)
vaValues(i, 1) = Left$(vaValues(i, 1), Len(vaValues(i, 1)) - 1)
Next i
Sheet1.Range("A2").Resize(UBound(vaValues, 1), UBound(vaValues, 2)).Value = vaValues
End Sub

Answer 2

You could do something like
Sub StringTrim()
Dim xCell as Range
Range("A1:A201").Select
For Each xCell in Selection
xCell.Value = Left(xCell.Value, Len(xCell.Value) - 1)
Next
End Sub
I don't know what kind of speed improvements you are seeking, but that would also do the job.
You might know this already but putting Application.ScreenUpdating = False at the top of your code can speed it up significantly (unless you like to watch everything flash by as the script works). You should reset the value to True at the end of your code.