Package body

Where the specification shows what the package provides, the body defines how things are done.

All a user of the package needs to know is what the package provides. The package is a "black box" to the user of the package. The package body is not visible to a package user.

General form of package body:

    package body package_name  is

        declarations

    end package_name ;

Notes:

• definitions (code) for subprograms declared in the specification
• supporting declarations may also be present (eg visible routines represent tasks, and extra routines are declared in the package body as subtasks in implementing the visible tasks).
• declarations are local - not visible to package user

Example

An example shows the implementation of a package of routines for working with rectangles, circles, etc.