topic Re: Do Loop in SAS Programming

Do Loop

swayto — Wed, 10 Apr 2019 08:30:17 GMT

Data Loop;
X=0;
do Index = 1 to 5 by 2;
x=Index;
end;
run;

X=5 , Index=7

Why is index=7.

gamotte — Wed, 10 Apr 2019 09:00:34 GMT

Hello,

When index=5 and the interpreter meets the "end" statements, il loops back to the do

statement, increments index by 2 and compare the result to 5 => index=7>5 so the loop stops.

andreas_lds — Wed, 10 Apr 2019 09:01:21 GMT

Adding a put statement in the loop could be helpful to understand what's happening.

Kurt_Bremser — Wed, 10 Apr 2019 11:11:40 GMT

A loop like yours is compiled to this (and the same is true for any programming language that has an iterative loop):

index = 1
start:
if index > 5 goto end
(loop code)
index + 2
goto start
end:

so you see that the index needs to go past the end value for the loop to exit.