*-------------------------------------------------------------
* The procedure returns a value of a 10-digit integer value.
* The 3 parameters are all 5-digit integers passed by value.
*-------------------------------------------------------------
D MyFunc PR 10I 0 EXTPROC('DO_CALC')
D 5I 0 VALUE
D 5I 0 VALUE
D 5I 0 VALUE
....
P DO_CALC B EXPORT
*-------------------------------------------------------------
* This procedure performs a function on the 3 numeric values
* passed to it as value parameters. It also returns a value.
*-------------------------------------------------------------
D DO_CALC PI 10I 0
D Term1 5I 0 VALUE
D Term2 5I 0 VALUE
D Term3 5I 0 VALUE
D Result S 10I 0
C EVAL Result = Term1 ** 2 * 17
C + Term2 * 7
C + Term3
C RETURN Result * 45 + 23
P E
*------------------------------------------------------------------
* CEETSTA (Test for omitted argument) -- ILE CEE API
* 1. Presence flag Output Binary(4)
* 2. Argument number Input Binary(4)
*------------------------------------------------------------------
D CEETSTA PR EXTPROC('CEETSTA')
D Present 10I 0
D ArgNum 10I 0 CONST
D Feedback 12A OPTIONS(*OMIT)
...
D HaveParm S 10I 0
...
C CALLP CEETSTA(HaveParm : 3 : *OMIT)
C IF HaveParm = 1
* do something with third parameter
C ENDIF
The second parameter passed to CEETSTA can be any numeric field, a literal, a built-in function, or expression.