Here's how I do it:

Any parameters that are required go first. Optional parameters follow. That way, I only have to do

IF PCOUNT() <= "number of required params"

Then for the optional parameters, I check the data type. If logical and false, it wasn't passed, so I give it a default value. Something like:

tcParam5 = IIF(VARTYPE(tcParam5) = "L" AND !tcParam5, "default value", tcParam5)

>This is a bit long, but I need to explain my question clearly.
>
>I want a consistant way to check parameters passed into COM objects.
>
>Right now, I use something like the following:
>
>

>PROCEDURE MyProc(aSomeArray AS Variant) AS Boolean HELPString "This method does..."
>WITH This
>
>  IF PCOUNT() = 1
>
>    IF TYPE("aSomeArray[1]") # T_UNDEFINED
>
>      ** Code for this method goes here
>									
>    ELSE
>      ERROR 232, "aSomeArray" && 'aSomeArray' is not an array
>    ENDIF
>			
>  ELSE
>    ERROR 1229 && Too few arguments
>  ENDIF
>
>ENDWITH
>

>
>Problem is, this is a lot of code for only 1 parameter. With methods that take 4 or 5 parameters, this
>could get really ugly.
>
>I am considering switching to something like:
>
>

>PROCEDURE MyProc(aSomeArray AS Variant) AS Boolean HELPString "This method does..."
>WITH This
>
> IF .CheckParams("MyProc", @aSomeArray)
>
>   ** Code for this method goes here
>
> ENDIF
>
>ENDWITH
>
>
>HIDDEN PROCEDURE CheckParams(sProcName, p1, p2, p3, p4, p5) AS Boolean
>
>  LOCAL bRetVal AS Boolean
>  bRetVal = TRUE
>
>  WITH This
>
>   DO CASE
>
>     CASE sProcName = "MyProc"
>      DO CASE
>        CASE TYPE("p1") # T_LOGICAL
>          ERROR 1229 && Too few arguments
>          bRetVal = TRUE
>
>        CASE TYPE("p1[1]") # T_UNDEFINED
>          ERROR 232, "aSomeArray" && 'aSomeArray' is not an array
>          bRetVal = TRUE
>
>      ENDCASE
>
>   ENDCASE
>
>  ENDWITH
>
>  RETURN bRetVal
>
>ENDPROC
>

>
>I welcome any thoughts/input on this.
>
>Thanks