Random number generation without repetition in SAS - sas

Question

I am trying to obtain random numer generation without repetition. My idea is to make do while loop which will go 5 times. Inside i will get the random numer, store it in the table and check at every iteration if the picked numer is in the table or not and then decide if this random pick is an repetition or not.
Here is my code where I try to perform my idea but something is wrong and i do not know where i made a mistake.
data WithoutRepetition;
counter = 0;
array temp (5) _temporary_;
do while(1);
rand=round(4*ranuni(0) +1,1);
if counter = 0 then
do;
temp(1) = rand;
counter=counter+1;
output;
continue;
end;
do a=1 to counter by 1;
if temp(a) = rand then continue ;
end;
temp(counter) = rand;
output;
counter=counter+1;
if counter = 5 then do;
leave;
end;
end;
run;

Answer 1

Sounds like you want a random permutation.
165 data _null_;
166 seed=12345;
167 array r[5] (1:5);
168 put r[*];
169 call ranperm(seed,of r[*]);
170 put r[*];
171 run;
1 2 3 4 5
5 1 4 3 2
This is a simplified version of what you are trying to do.
data WithoutRepetition;
i=0;
array temp[5];
do r=1 by 1 until(i eq dim(temp));
rand=round(4*ranuni(0)+1,1);
if rand not in temp then do; i+1; temp[i]=rand; end;
end;
drop i rand;
run;

Answer 2

You were reasonably close to a working, if convoluted solution. For educational purposes, although data _null_'s answer is much cleaner, here's why your code wasn't working:
Your leave statement is inside a do-end block which is inside another do-loop. Leave statements only break out of the innermost do-loop, so yours has no effect.
The same is true of your continue statements, the first of which is completely unnecessary.
Because you are updating your array with newly-found unique values before you increment counter, previously populated values are being overwritten. This often results in duplicates of the overwritten values appearing in your output.
I would place continue and leave in the same category as goto - avoid using them if at all possible, as they tend to make code difficult to debug. It's clearer to set the exit conditions for all your loops at the point of entry.
Just for fun, though, here's a fixed version of your original code:
data WithoutRepetition;
counter = 0;
array temp (5) _temporary_;
do while(1);
rand=round(4*ranuni(0) +1,1);
if counter = 0 then do;
temp(1) = rand;
counter +1;
output;
end;
dupe = 0;
do a=1 to counter;
if temp(a) = rand then dupe=1;
end;
if dupe then continue;
counter +1;
temp(counter) = rand;
output;
if counter = 5 then leave;
end;
run;
And here is an equivalent version with all the leave and continue statements replaced with more readable alternatives:
data WithoutRepetition;
counter = 0;
array temp (5) _temporary_;
do while(counter < 5);
rand=round(4*ranuni(0) +1,1);
if counter = 0 then do;
temp(1) = rand;
counter +1;
output;
end;
else do;
dupe = 0;
do a=1 to counter while(dupe = 0);
if temp(a) = rand then dupe=1;
end;
if dupe = 0 then do;
counter +1;
temp(counter) = rand;
output;
end;
end;
end;
run;