1# saslovime Quote the string ‘1=1’ at macro compile time. Without quoting, the string may be resolved in an unexpected way at some cases, even I did not see what the quotation exactly functions here.

You are right.

But it still seems to the %str here is redundant because (1=1) is a legitimate expression with no 'confusion'.


145  data _null_;
146    sourceSubset=1;
147    if sourceSubset=%str(1=1) then put '1';
148    else put '0';
149    run;

1
NOTE: DATA statement used (Total process time):
      real time           0.00 seconds
      cpu time            0.00 seconds


150
151    %macro t(d);
152       %let  sourceSubset=1;
153       %if &sourceSubset=%str(1=1) %then %put >>>1;
154       %else %put >>>0;
155    %mend;
156
157    %t(d);
>>>0

%str就是为了让一些类似等号的特殊符号可以解析。

学习了

%str是屏蔽掉一些特殊的符号:如（ ，），%等；上面的程序是返回一个逻辑表达式的值