A PSPP variable is represented by
struct variable, an opaque type
declared in data/variable.h along with related declarations.
See Variables, for a description of PSPP
variables from a user perspective.
PSPP is unusual among computer languages in that, by itself, a PSPP variable does not have a value. Instead, a variable in PSPP takes on a value only in the context of a case, which supplies one value for each variable in a set of variables (see Cases). The set of variables in a case, in turn, are ordinarily part of a dictionary (see Dictionaries).
Every variable has several attributes, most of which correspond directly to one of the variable attributes visible to PSPP users (see Attributes).
The following sections describe variable-related functions and macros.