Resolves the value of a text expression during DATA step execution
- can be
- a text expression enclosed in single quotation marks (to prevent
the macro processor from resolving the argument while the DATA step is being
constructed). When a macro variable value contains a macro variable reference,
RESOLVE attempts to resolve the reference. If argument references
a nonexistent macro variable, RESOLVE returns the unresolved reference. These
examples using text expressions show how to assign the text generated by macro
LOCATE or assign the value of the macro variable NAME:
- the name of a DATA step variable whose value is a text expression.
For example, this example assigns the value of the text expression in the
current value of the DATA step variable ADDR1 to X:
- a character expression that produces a text expression for resolution
by the macro facility. For example, this example uses the current value of
the DATA step variable STNUM in building the name of a macro:
The RESOLVE function returns a character
value that is the maximum length of a DATA step character variable unless
you explicitly assign the target variable a shorter length. A returned value
that is longer is truncated.
If RESOLVE cannot locate the macro variable or macro identified by the
argument, it returns the argument without resolution and the macro processor
issues a warning message.
You can create a macro variable with the SYMPUT routine and use RESOLVE
to resolve it in the same DATA step.
- RESOLVE resolves the value of a text expression during execution
of a DATA step or SCL program, whereas a macro variable reference resolves
when a DATA step is being constructed or an SCL program is being compiled.
For this reason, the resolved value of a macro variable reference is constant
during execution of a DATA step or SCL program. However, RESOLVE can return
a different value for a text expression in each iteration of the program.
- RESOLVE accepts a wider variety of arguments than the SYMGET function
accepts. SYMGET resolves only a single macro variable but RESOLVE resolves
any macro expression. Using RESOLVE may result in the execution of macros
and resolution of more than one macro variable.
- When a macro variable value contains an additional macro variable
reference, RESOLVE attempts to resolve the reference, but SYMGET does not.
- If argument references a nonexistent macro variable,
RESOLVE returns the unresolved reference, whereas SYMGET returns a missing
- Because of its greater flexibility, RESOLVE requires slightly
more computer resources than SYMGET.
This example shows RESOLVE
used with a macro variable reference, a macro invocation, and a DATA step
variable whose value is a macro invocation.
length var1-var3 $ 15;
var1=resolve('&event'); /* macro variable reference */
var2=resolve('%date'); /* macro invocation */
var3=resolve(when); /* DATA step variable with macro invocation */
put var1= var2= var3=;
Executing this program writes these lines to the SAS log:
VAR1=Holiday VAR2=New Year VAR3=New Year
NOTE: The data set WORK.TEST has 1 observations and 4 variables.
Copyright 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.