Passing parameters by reference

[OhioJoe]

This works in VO

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LOCAL cParam AS STRING
cParam := " "
Joe( @cParam )
?cparam  // expecting it to be "Hello"

FUNCTION Joe( cString AS USUAL ) AS VOID STRICT
	cString := "Hello"
	RETURN

But when I try in X# I get the following error:

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error XS9109: Argument 1 may not be passed with the '@' prefix	

nor does it allow the "REF" keyword

??

Thanks in advance for any help

[Chris]

Hi Joe,

This indeed works in VO, but it shouldn't since the function is strongly typed to be accepting a USUAL by value, but the code is doing something very different, it is passing a STRING by reference.

If you change it to accept a STRING by reference, then it will work:

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FUNCTION Joe( cString REF STRING ) AS VOID STRICT

or you can define it to accept a USUAL by reference and instead type your LOCAL cParam AS STRING instead of USUAL:

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LOCAL cParam AS USUAL
FUNCTION Joe( cString REF USUAL) AS VOID STRICT

Finally, you could also remove strong typing form the function and it will work either way:

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FUNCTION Joe( cString ) AS VOID CLIPPER

but I would not suggest to do this, since you will lose all compile time checking.

[OhioJoe]

Thank you, Chris.