[Solved] - Extract last n-characters from Form input

[scottgm23]

Hello everyone, 

I have a pretty simple requirement but I can't seem to figure out how to achieve this in Flow. 

I have a form where a user is requested to input an ID number with or without the leading characters, such as:

XYZ000000333222

333222

XYZ333222

XYZ000333222

I am only interested in the last 6 characters of their input (333222 in this example) as I can modify the string later in SharePoint when I do a DB lookup. Using a regular expression ((.{6})\s*$) this is very simple but I'm not sure how to achieve this using a substring or split or some other expressions within Flow.

[AlanPs1 · Accepted solution]

Hi @scottgm23 , thank you for your post.

I have simulated your form input by using "Compose Input" below:

sub(length(outputs('Compose_Input')), 6)

substring(outputs('Compose_Input'), int(outputs('Compose_Number_Of_Characters_In_Input')), 6)

Regardless of what the input is, this method will get you the last 6 digits of the ID number.

If you have found my post helpful, please mark thumbs up.

Any other questions, just ask.

Thanks, Alan

[scottgm23]

Many thanks @AlanPs1 , I appreciate you taking the time to help.

After some more trial and error, I figured out that I needed to calculate the index value for the substring and then arrived at the same solution as you(well almost). I didn't specify INT in the last subsubstring value but it worked either way. 

[AlanPs1]

That's great @scottgm23 .

int() not always required but Flow tends to output to string unless told otherwise so it's a safer option a lot of the time.

I'm glad you have it working!

Happy Flowing!

Thanks, Alan

[AGoh]

Stumbled upon this post when trying to find a solution for the problem I'm facing which is very similar to this one that @scottgm23 was facing. and thanks @AlanPs1 for the solution.

After some running some tests, I figured out actually there is a way to reduce the steps by merging the last two steps. Using @AlanPs1 's solution above as example, i.e.

substring(outputs('Compose_Input'), int(sub(length(outputs('Compose_Input')), 6)), 6)

[CW]

Thanks AlanPs1. You have no idea how much this helped, and how much I learned by having a workable technique.

Cheers