Extending an Interface

Purpose:

To create an interface which inherits from one or more other interfaces.

Mechanics:

<modifiers> interface
<interface name> extends <superinterface
list> {

/* Class constants and abstract
methods declared here */

}

Example:

public interface myInterface
extends superInterface {

/* Class constants and abstract
methods declared here */

}

Usage:

<modifiers> is an optional space-separated list of valid interface modifiers.
<interface name> is a valid identifier unique to the current scope.
<superinterface list> is a comma-separated list of interfaces from which this interface should inherit.
<interface name> will inherit all the method declarations and class constants in each of the interfaces listed in <superinterface list>. Thus the methods and class constants defined for <interface name> need be only those things needed to specialize the interface.
Any of the interfaces in <superinterface list> may also inherit methods and class constants; if so, <interface name> inherits everything that these interfaces inherit.
Variables may be declared of type <interface name> and defined as a class that implements the interface. Such references respond to all methods declared in the interface, or in any of its superinterfaces.

Restrictions:

Note that there is no analogue of the class Object for interfaces; that is, while every class inherits from class Object, there is no single interface from which all interfaces inherit.

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