Hello all. I am a novice SAS user, mostly base, though have used and slightly manipulated programs using proc sql, macros etc.   I recently faced some tough (from my perspective) questions in an interview for a position that uses SAS. I am asking from memory, but was hoping someone could take the time to explain in slight detail some of the answers (or HOW i should have answered here).   1) Look at this sample code   proc sql; create table C as select A.VA, B.VB, from A left join B on strip(A.VA) = strip(B.VA) order by VA; Quit;   Please describe what this does and the exact detail of the output dataset C  (Variables and observations)?   2) How do you use the do loop if you don’t know how many times you should execute the do loop?   3) How many ways to create a format using Proc Format?   4) Can you explain the differences between a macro program and a macro variable?   5) How many ways are there to create a macro variable?     I feel like I must have done very poorly on these, and rather than spend more time researching in looking it up I am asking for some help as a relatively novice user. Any help appreciated. Thank you.   Cristoban ... View more