One Range within Another

Excel has sophisticated methods available for users but it is easy to misunderstand what the program designer really meant. The Intersect method could be one of these.

I first used the method a little over 20 years ago. It allowed me to post a value in named column, in respect of specific transaction (formed by a row). At that time, the real advantage of this approach the location of the column could change without my having to rewrite the code. It would continue to be posted to the correct cell for the purposes of the overall program.

My current task – one range within another - sounds very similar. Indeed, when searching the web, the Intersect method was offered as a potential solution. However, there are some crucial / fundamental differences.

I was not looking for overlapping ranges. Rather, the whole of the smaller range had to be contained within the boundaries of the larger one. It became clear that I had examine each of the boundaries of the larger range individually and compare them with the equivalent boundaries of the smaller one. Only if all four comparisons were valid could I be sure that no part smaller range stepped outside the boundary of the larger one. This led to some rather tediously long-winded code shown below.

Image of VB code

Mistakes in code development – or are they?

The expectation of the code above is that the larger and smaller ranges will be on the same worksheet, but the requirement is not actually specified. So, I considered what the implications might be if the two ranges were on different worksheets.

• The code relies exclusively on the numerical values of the boundary positions of the larger and smaller ranges. If those boundary positions were satisfied then the function would still deliver a TRUE result. At first, this seemed a perfectly worthless truism.
• It then occurred to me that the code was written, assuming that the smaller range was indeed smaller. However, it was also written such that the individual boundaries could be the same. Taken to its logical conclusion, all four boundaries of the so called larger and smaller ranges could be the same.

Taking these two conclusions together, we have a methodology for proving that two ranges on different worksheets are of identical size and in identical locations.

Sheet1

Sheet2

This sounds more like a silly panel game from the BBC’s ‘I’m Sorry I haven’t aClue’, but, if anyone can identify a genuine use for the function, I'd be delighted.