Chapter 3
Rules for Words and Names in the
SAS Language
Words in the SAS Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Definition of Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Types of Words or Tokens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Placement and Spacing of Words in SAS Statements . . . . . . . . . . . . . . . . . . . . . . . 23
Names in the SAS Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Definition of a SAS Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Rules for User-Supplied SAS Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SAS Name Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Summary of Default Rules for Naming SAS Data Sets and SAS Variables . . . . . . 33
Summary of Extended Rules for Naming SAS Data Sets and SAS Variables . . . . . 34
Words in the SAS Language
Definition of Word
A word or token in the SAS programming language is a collection of characters that
communicates a meaning to SAS and which cannot be divided into smaller units that can
be used independently. A word can contain a maximum of 32,767 bytes.
A word or token ends when SAS encounters one of the following:
• the beginning of a new token
• a blank after a name or a number token
• the ending quotation mark of a literal token
Each word or token in the SAS language belongs to one of four categories:
• names
• literals
• numbers
• special characters
Types of Words or Tokens
There are four basic types of words or tokens:
21
name
is a series of characters that begin with a letter or an underscore. Later characters can
include letters, underscores, and numeric digits. A name token can contain up to
32,767 bytes. In most contexts, however, SAS names are limited to a shorter
maximum length, such as 32 or 8 bytes. See Table 3.1 on page 25. Here are some
examples of name tokens:
• data
• _new
• yearcutoff
• year_99
• descending
• _n_
literal
consists of 1 to 32,767 bytes enclosed in single or double quotation marks. Here are
some examples of literals:
• 'Chicago'
• "1990-91"
• 'Amelia Earhart'
• 'Amelia Earhart''s plane'
• "Report for the Third Quarter"
Note: The surrounding quotation marks identify the token as a literal, but SAS does
not store these marks as part of the literal token.
number
in general, is composed entirely of numeric digits, with an optional decimal point
and a leading plus or minus sign. SAS also recognizes numeric values in the
following forms as number tokens: scientific (E−) notation, hexadecimal notation,
missing value symbols, and date and time literals. Here are some examples of
number tokens:
• 5683
• 2.35
• 0b0x
• -5
• 5.4E-1
• '24aug90'd
special character
is usually any single keyboard character other than letters, numbers, the underscore,
and the blank. In general, each special character is a single token, although some
two-character operators, such as ** and <=, form single tokens. The blank can end a
name or a number token, but it is not a token. Here are some examples of special-
character tokens:
• =
• ;
• '
22 Chapter 3 • Rules for Words and Names in the SAS Language
• +
• @
• /
Placement and Spacing of Words in SAS Statements
Spacing Requirements
Here are the spacing requirements for words in SAS statements:
• You can begin SAS statements in any column of a line and write several statements
on the same line.
• You can begin a statement on one line and continue it on another line, but you cannot
split a word between two lines.
• A blank is not treated as a character in a SAS statement unless it is enclosed in
quotation marks as a literal or part of a literal. Therefore, you can put multiple blanks
any place in a SAS statement where you can put a single blank. It has no effect on
the syntax.
• The rules for recognizing the boundaries of words or tokens determine the use of
spacing between them in SAS programs. If SAS can determine the beginning of each
token due to cues such as operators, you do not need to include blanks. If SAS
cannot determine the beginning of each token, you must use blanks. See Examples
on page 23.
Although SAS does not have rigid spacing requirements, SAS programs are easier to
read and maintain if you consistently indent statements. The examples illustrate useful
spacing conventions.
Examples
• In this statement, blanks are not required because SAS can determine the boundary
of every token by examining the beginning of the next token:
total=x+y;
The first special-character token, the equal sign, marks the end of the name token
total. The plus sign, another special-character token, marks the end of the name
token x. The last special-character token, the semicolon, marks the end of the y
token. Though blanks are not needed to end any tokens in this example, you can add
them for readability, as shown here:
total = x + y;
• This statement requires blank spaces because SAS cannot recognize the individual
tokens without them:
input group 15 room 20;
Without blanks, the entire statement up to the semicolon fits the rules for a name
token: it begins with a letter or underscore, contains letters, digits, or underscores
thereafter, and is less than 32,767 bytes long. Therefore, this statement requires
blanks to distinguish individual name and number tokens.
Words in the SAS Language 23
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