Length of a variable created by a PROC FCMP character function

[SR_FR]

Hi,

When you use for instance the SUBSTR function to create a new variable, the length of that new variable is equal to the length of the variable you use as an argument.

I created a character function with PROC FCMP and I'd like my function to have the same property.

If my function statement is like this :

function extrait(chaine $,dlm $,pos) $ ;

The length of the variable created when I use this function is 33 (BTW, why?). I can give an arbitrary large value for the length of the created variables (say 500...) but this would be a waste of resources.

I'd like that length to be equal to the length of the variable I'll use as the "chaine" argument.

is this possible?

best regards

Sébastien

[ballardw · Accepted solution]

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@SR_FR wrote:

Hi,

When you use for instance the SUBSTR function to create a new variable, the length of that new variable is equal to the length of the variable you use as an argument.

I created a character function with PROC FCMP and I'd like my function to have the same property.

If my function statement is like this :

function extrait(chaine $,dlm $,pos) $ ;

The length of the variable created when I use this function is 33 (BTW, why?). I can give an arbitrary large value for the length of the created variables (say 500...) but this would be a waste of resources.

I'd like that length to be equal to the length of the variable I'll use as the "chaine" argument.

is this possible?

best regards

Sébastien

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Likely the reason your test variable has length of 33 is the first returned value had that length. The basic rule for non-defined lengths of character variables is the first use will set the length.

The easiest I could see if you don't want to be bothered to assign an explicit length to a "new" variable is to do something such as call to substr or similar function prior to the function call:

dummy = substr(var,1);

dummy = extrait(var, ',',3) ; (or however you want to call your function.

[SR_FR]

the solution your propose does the job !

thanks!

about the 33, well, it's still a mystery...

The first returned value can not help to understand this length since the length of a character variable is decided during the compilation of the program.

may be the complete program would help to solve the mystery...

proc fcmp outlib=sasuser.funcs.temp;
   function extrait(chaine $,dlm $,pos) $ ;
   temp=0;
      do i=1 to pos;
         temp=find(chaine,dlm,temp+1);
      end;
   return(substr(chaine,1,temp-1));
   endsub;
run;

options cmplib=sasuser.funcs;

data toto;
   x="azz,bs,cezz,dd,e";
   y=3;
   dlm=',';
   gogo=extrait(x,dlm,y);
run;

Sébastien