Component Variable Access Modes and Modifiers

The access attribute for a component variable controls what can access the variable. There are four access modes, public, private, path, and protected. If the access mode is set to public, then access to the variable is not restricted in any way. If the access mode is set to protected, then access to the variable is restricted to derived components and entities in the same path. If the access mode is set to path, then access to the variable is restricted to entities in the same path. If the access mode is set to private, then access to the variable is restricted to the component containing the variable. The default access mode for a component is public.

The modifiers, abstract and final, for a component variable effect the default values and overrides for a component variable. If the modifier is set to abstract then the variable default attribute is omitted and must be specified by non-abstract derived components. Variables can only be declared abstract if the component is also declared abstract. Abstract variables may not be private. Non-abstract variables must declare a default value. If the modifier is set to final then the variable may not be overridden by derived components. If the modifier is omitted, then derived components can choose whether or not to override the variable.