Manipulate Data Table Column With Formula

I need to apply a formula to an entire column and copy into a new datatable. I don’t want to use a For Each loop since sometimes these tables have a LOT of lines.

I have a column where negative values have the “-” at the end, so I need an if statement to parse and convert to double. The if is pretty straight forward, but I’m not sure how to phase the Enumerable expression
Before:

Col1 Col2
Text1 123
Text2 123-
Text3 1234

After:

Col1 Col2
Text1 123
Text2 -123
Text3 1234

Before:
image

Logic:

First use read Range activity for getting all value from excel and stored in datatable variable like(Ex: dt_test)

then use For Each Row Activity with indexnum integer type and put If Condition in for each row

then Use If Condition and condition is (row(1).toString.EndsWith("-"))

Here I m using Row(1) for col 2.

Then use Write cell Activity for to get output like:

image

Thanks
Let me know still if you have any doubt

Hi, I said I don’t want to use a For Each activity. These tables can get really big and I’m looking for a more efficient way to do it.

@Wil_Lee - Please check the below

string.Format("{0}{1}", Str.Substring(Str.Length - Length),Str.Substring(0, Str.Length - Length))

Output:

image

@Wil_Lee - Any update on this?

No this only transforms the string which is not the issue here. The original ask was how to apply an efficient transformation on an entire datatable column. Efficient being, not using a for each loop as sometimes these tables have 50,000+ rows.