How to find the comma's in the string dynamically?

[Saikiran_Mamidi]

Interview Question to my friend.

x=A,B,C,D,E,F,G ;

He wants  to find 4th  comma or 5th comma.

I have given this answer.

data a;
x='A,B,C,D,E,F';
run;
%let p=9;
data find_comma;
set a;
fouth_comma=find(x,',',&p);
run;

Is it correct? or wrong?

Interview asked me to write dynamically. 

Please correct if I'm  wrong.

They want dynamically?

[Ksharp]

data _null_;
x='A,B,C,D,E,F';

n=4;
call scan(x,n,p,l,',');
position=p+l ;
putlog 'n=' n 'position=' position;


n=5;
call scan(x,n,p,l,',');
position=p+l ;
putlog 'n=' n 'position=' position;

run;

[andreas_lds]

Have a look at https://blogs.sas.com/content/sgf/2019/06/26/finding-n-th-instance-of-a-substring-within-a-string/

[gamotte]

Hello,

data _null_;
    x='A,B,C,D,E,F';

    do n=4, 5;
        position=length(prxchange(cats('s/^(([^,]*,){',n,'}).*$/$1/'),1,x));
        put n= position=;
    end;
run;