Macro Statements |
Type: | Macro statement |
Restriction: | Allowed in macro definitions only |
See also: | %GLOBAL Statement |
Syntax | |
Details | |
Comparisons | |
Example | |
Using a Local Variable with the Same Name as a Global Variable |
Syntax |
%LOCAL macro-variable-1 <...macro-variable-n>; |
is the name of one or more macro variables or a text expression that generates one or more macro variable names. You cannot use a SAS variable list or a macro expression that generates a SAS variable list in a %LOCAL statement.
Details |
The %LOCAL statement creates one or more local macro variables. A macro variable created with %LOCAL has a null value until you assign it some other value. Local macro variables are variables that are available only during the execution of the macro in which they are defined.
Use the %LOCAL statement to ensure that macro variables created earlier in a program are not inadvertently changed by values assigned to variables with the same name in the current macro. If a local macro variable already exists and you specify that variable in a %LOCAL statement, the existing value remains unchanged.
Comparisons |
Both the %LOCAL statement and the %GLOBAL statement create macro variables with a specific scope. However, the %LOCAL statement creates local macro variables that exist only during the execution of the macro that contains the variable, and the %GLOBAL statement creates global macro variables that exist for the duration of the session or job.
If you define a local macro variable and a global macro variable with the same name, the macro facility uses the value of the local variable during the execution of the macro that contains that local variable. When the macro that contains the local variable is not executing, the macro facility uses the value of the global variable.
Example |
%let variable=1; %macro routine; %put ***** Beginning ROUTINE *****; %local variable; %let variable=2; %put The value of variable inside ROUTINE is &variable; %put ***** Ending ROUTINE *****; %mend routine; %routine %put The value of variable outside ROUTINE is &variable;
Submitting these statements writes these lines to the SAS log:
***** Beginning ROUTINE ***** The value of variable inside ROUTINE is 2 ***** Ending ROUTINE ***** The value of variable outside ROUTINE is 1
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