how can i replace multiple varibale

[Aayushi_17]

what function can i use to replace the variable with 4  in the place of 4 or multiples of 4 ??

the input  is  

data one ;
a='abcdefghijklmnopqrstuvwx';
run; 

the output i want is :

 abc4efg4hij4lmn4pqr4tuv4

[error_prone]

Can't test the code now, try something like:

data work.want;
a ='abcdefghijklmnopqrstuvwx';

do i = 1 to lengthen(a);
if int(i/4) = 0 then do;
substr(a, i, 1) = '4';
end;
end;
run;

[DanielLangley · Accepted solution]

I think you made a mistake in your wanted output.

You put abc4efg4hij4lmn4pqr4tuv4 when I believe it is abc4efg4ijk4mno4qrs4uvw4. The problem being that h.

Try this.

data work.want;
attrib 	a format = $50.
		want format = $50.
;


a ='abcdefghijklmnopqrstuvwx';
array lettersInA[26] $ _TEMPORARY_;


do i = 1 to lengthn(a);
	if mod(i,4) = 0 then lettersInA[i] = "4";
	else lettersInA[i] = substr(a,i,1);
end;

want = cats(of lettersInA[*]);
drop i;
run; 

[Ksharp]

data _null_;
a ='abcdefghijklmnopqrstuvwx';
put a=;
do i = 4 to length(a) by 4;
substr(a, i, 1) = '4';
end;
put a=;
run;

[Aayushi_17]

thank you so much this worked