how to pass multiple optional parameters to a custom function?

[jnixon]

I've experimented, but I have not come up with a solution for this scenario:

My Custom function accepts three parameters, the last two of which are optional. I want to pass parameters one and three only. How do I call the function?

[Anonymous · Accepted solution]

Make sure that your second argument has no type. You will then be allowed to pass a null value as the second option. 

[jnixon]

Thanks Mike - back to the rescue!

That works indeed.  Testing further, i found that this will also work with passing null, and with the added benefit of validating the data type of the parameters:

(P1 as text, optional P2 as nullable text, optional P3 as nullable text) =>

let

   T1 = "P1 = " & P1,

   T2 = if (P2 = null) then "; P2 = null()" else "; P2 = " & P2,

   T3 = if (P3 = null) then "; P3 = null()" else "; P3 = " & P3,

   Return = T1 & T2 & T3

in

   Return

[Anonymous]

Hey J, I forgot that you could use nullable text. I wish more of the standard PQ functions would use them.