This section deals with the data-storage elements of Fortran: constants, variables,
and arrays. These all possess an important property called data type. The data type
of an item determines what sort of information it holds and the operations that can
be performed on it.
5.1 Data Types
5.2 Constants
5.3 Specifying Data Type
5.4 Named Constants
5.5 Variables
5.6 Arrays
