%LET macro statement

The %LET macro statement or %LET statement is a SAS macro language statement that assigns text to a macro variable.

Syntax

%LET identifier = text ;

identifier is the name of any valid SAS macro variable.
text is the text to be assigned to the macro variable. The text can include macro variables, macro quoting functions and escaped characters. However, leading and trailing blank spaces surrounding the text are ignored.

Usage

The %LET macro statement can be used in open code. It is often used at the beginning of a program to provide parameter values or settings for the code that follows. This avoids needing to hard code values in other parts of a program and makes a program more maintainable.

If some or all of the text is contained in another macro variable then that macro variable name needs to be preceded by an ampersand symbol (&). Also, that macro variable name needs to be followed by a period (.) if there is no trailing space or other character that identifies the starts of a new token. This is so the macro language parser can tell where the macro variable name ends, so it will not misinterpret trailing text as part of the macro variable name.

Various quoting and unquoting macro functions can also be used to hide characters from the parser, so they can be assigned as as text.

%LET statements are useful for setting constant text values that can be substituted in one or more places in subsequent code. They can assist in making code more reusable.