SAS recognizes four general types of tokens:
One or more characters
enclosed in single or double quotation marks. Examples of literals
include the following:
One or more characters
beginning with a letter or an underscore. Other characters can be
letters, underscores, and digits.
A numeric value. Number
tokens include the following:
-
integers. Integers are numbers
that do not contain a decimal point or an exponent. Examples of integers
include 1, 72, and 5000. SAS date, time, and datetime constants such
as '24AUG2008'D are integers, as are hexadecimal constants such as
0C4X.
-
real (floating-point) numbers.
Floating-point numbers contain a decimal point or an exponent. Examples
include numbers such as 2.35, 5., 2.3E1, and 5.4E− 1.
Any character that
is not a letter, number, or underscore. The following characters are
some special characters:
The maximum length of
any type of token is 32,767 characters. A token ends when the tokenizer
encounters one of the following situations:
-
the beginning of a new token.
-
a blank after a name or number
token.
-
in a literal token, a quotation
mark of the same type that started the token. There is an exception.
A quotation mark followed by a quotation mark of the same type is
interpreted as a single quotation mark that becomes part of the literal
token. For example, in
'Mary''s', the fourth
quotation mark terminates the literal token. The second and third
quotation marks are interpreted as a single character, which is included
in the literal token.