SAS 宏中这段代码的逻辑是什么？

Question

%let x = 15;


  %macro test;
        %let x = 10;
        %put x inside macro test = &x;
    %mend test;

    %test;

    %put x outside the macro test =&x;
    %put x inside the macro test =&x;

我想知道宏定义之外的test值是多少？

Answer 1

如果宏变量是在全局范围内定义的，即您的 %LET X = 15;，那么宏中对该宏变量的任何更改都会影响全局值，除非您在宏中使用 [= 显式覆盖它11=].

%let x = 15; /* Global X = 15 */

%macro test;
   %let x = 10; /* Global X = 10 */
   %put x inside macro test = &x; /* 10 */
%mend test;
%test;

%put x outside the macro test =&x; /* 10 */

但是 %LOCAL

%let x = 15; /* Global X = 15 */

%macro test;
   %local x;
   %let x = 10; /* Local X = 10 */
   %put x inside macro test = &x; /* 10 */
%mend test;
%test;

%put x outside the macro test =&x; /* 15 */

SAS 宏中这段代码的逻辑是什么？

what is the logic of this code in SAS Macros?

sas

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