Sas Delete and Return Statements
I'm Looking at Someone Else's Code and Trying to Determine If: If X = Y Then Do; Delete; Return; End; Is Equivalent to: If X = Y Then Do; Delete; End; from the...
I'm looking at someone else's code and trying to determine if:
if x = y then do;
delete;
return;
end;
is equivalent to:
if x = y then do;
delete;
end;
From the documentation on DELETE:
When DELETE executes, the current observation is not written to a data set, and SAS returns immediately to the beginning of the DATA step for the next iteration.
Which leads me to believe the 'return' statement in the first example is not executed?
1 Answer
May as well test, rather than guess.
- Create a data set with x/y values, one that will meet the condition and one that will not.
- Run the data step and add PUT statement so you can trace the log
From the log you see that nothing after the DELETE is executed, so you can confirm that RETURN is not executed and is redundant.
FYI - one thing to consider - has this behaviour changed over time or has the code changed where perhaps this was once valid? Usually that's the case.
data have;
input x y;
cards;
1 2
1 1
;;;;
run;
data demo;
set have;
if x = y then do;
put "Record Deleted 1";
delete;
put "Record Deleted 2";
return;
put "Record Deleted 3";
end;
else put "Record Retained";
run;
Log:
78 data demo;
79 set have;
80 if x = y then do;
81 put "Record Deleted 1";
82 delete;
83 put "Record Deleted 2";
84 return;
85
86 put "Record Deleted 3";
87
88 end;
89 else put "Record Retained";
90
91 run;
Record Retained
Record Deleted 1
NOTE: There were 2 observations read from the data set WORK.HAVE.
NOTE: The data set WORK.DEMO has 1 observations and 2 variables.
NOTE: DATA statement used (Total process time):
real time 0.00 seconds
user cpu time 0.00 seconds
system cpu time 0.00 seconds
memory 798.71k
OS Memory 24232.00k
Timestamp 10/18/2021 10:25:05 PM
Step Count 39 Switch Count 2
Page Faults 0
Page Reclaims 135
Page Swaps 0
Voluntary Context Switches 10
Involuntary Context Switches 0
Block Input Operations 0
Block Output Operations 264
Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.
