- data profit errors;
- set chapt2.expenses;
- set chapt2.income key = dteflt;
- if _iorc_ = 0 then do;
- profit =sum(income,- expenses);;
- output profit;
- end;
- else do;
- _error_ = 0;
- output errors;
- end;
- run;
当key匹配不对时_iorc_=1,_error_=1
那else do下的_error_=0这句的作用是啥?重新置为0么,如果不要可以吗?
还有,_iorc_变量除了和key匹配有关,还会在什么情况下产生?