Does anybody know what this function in formulas does?

Because I cannot find any details online.

=Optional(expression, replacement_expression)

Regards,

Robert

I've not seen that one before but by looking at the formula it seems to find a particular item and replace it with something else i.e. =optional("Apples","Oranges") 

Happy to be corrected on that but seems the most logical answer 

Found a formula in a perspective Remaining Spend:

=Amount - (YearToDate(Payables)) - optional(Purchase Orders Master Data.Prior Monetary Amount,0)

And my conclusion is that it's a reporting function, where if the value doesn't exist, the value (in this case) is 0 and otherwise the value is: Purchase Orders Master Data.Prior Monetary Amount

I had a feeling it would work similar to what @Robert Brilmayermentioned.

Here's another way of how I tested it out....

Period 1 Source File

Field Name = Cost Object Id

Period 2 Source File

Field Name = Cost Object ID

Notice the renamed field in Period 2 where the suffix's lettering is all caps.

How do I accommodate the use of the two variations?

Using the Optional function!!! 

New Field "Cost Object Code"

=Optional(Cost Object Id,Cost Object ID)

LOVE THIS!!! 

Here's a screenshot of a before and after approach taken on one of my tables...

Thanks to @Robert Brilmayer, @Matt Temple, and @Julie Batty. I learnt something today. This is super helpful to select columns in a specific order based on their value. 

Thanks!

Just asked our CSM to get an update done for the list of functions.