The USE statement gives a program unit accessibility to public entities in a module. For more information, see USE in the A to Z Reference.
Examples
Entities in modules can be accessed either through their given name, or through aliases declared in the USE statement of the main program unit. For example:
USE MODULE_LIB, XTABS => CROSSTABS This statement accesses the routine called CROSSTABS in
MODULE_LIB by the name XTABS. This way, if two
modules have routines called CROSSTABS,
one program can use them both simultaneously by assigning a local name
in its USE statement.
When a program or subprogram renames a module entity, the local name
(XTABS, in the preceding example) is accessible throughout the scope of
the program unit that names it.
The ONLY option also allows public variables to be renamed. Consider the following:
USE MODULE_A, ONLY: VARIABLE_A => VAR_A In this case, the host program accesses only VAR_A from
module A, and refers to it by the name VARIABLE_A.
Consider the following example:
MODULE FOO
integer foos_integer
PRIVATE
integer foos_secret_integer
END MODULE FOO
PRIVATE, in this case, makes the PRIVATE attribute the default
for the entire module FOO. To make foos_integer
accessible to other program units, add the line:
PUBLIC :: foos_integer Alternatively, to make only foos_secret_integer inaccessible
outside the module, rewrite the module as follows:
MODULE FOO
integer foos_integer
integer, private::foos_secret_integer
END MODULE FOO