Variable names are important in data analysis and administration in SAS (Statistical Analysis System). The following are the main principles for naming SAS variables:
- Characters that are acceptable:
Variable names must start with a letter (A-Z) or an underscore (_).
You can use letters, numerals (0-9), or underscores after the first character.
Variable names cannot contain special characters such as @, #, $, %, and so on.
- Length:
Variable names can contain up to 32 characters.
- Sensitivity to Cases:
The names of SAS variables are not case sensitive. “Age,” “age,” and “AGE” all refer to the same variable.
- Reserved Phrases:
Avoid utilising SAS reserved terms as variable names (e.g., if, then, else, do, end, retain, etc.).
- Names with only numbers:
While it is possible to have variable names that are only integers, it is typically not advised because it might cause confusion.
- Considerations for Numerical Variables:
If you want to utilise numeric variables with leading zeros (for example, 00123), you must use a format or informat to retain the leading zeros.
- Characters of Interest:
The periods (.) and hyphens (-) are permitted in variable names, although they have different meanings in SAS:
The period (.) character is used to express a range of variables (for example, var1-var5).
The hyphen (-) is used for subtraction and must be surrounded in square brackets in variable names (e.g., [var-name]).
- Conventions for Naming:
It’s a good idea to give variables meaningful and descriptive names that reflect the facts they represent. For example, “Age” rather than “Var1.” Leading Spaces:
- Variable names should not begin with a space.
- Trailing Areas:
Variable names should not contain any spaces.
- Case Persistence:
While SAS does not care about case in variable names, it is recommended to use consistent casing for variable names inside your dataset (e.g., always use lowercase or uppercase).
- Special Characters Should Be Avoided:
While some special characters are permitted, it is best to avoid them in variable names to guarantee compatibility and readability.