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Interfaces

Like a class, an interface defines a new reference type. Unlike classes, however, interfaces provide no implementation for the types they define. As its name implies, an interface specifies only an API: all of its methods are abstract and have no bodies. It is not possible to directly instantiate an interface and create a member of the interface type. Instead, a class must implement the interface to provide the necessary method bodies. Any instances of that class are members of both the type defined by the class and the type defined by the interface. Interfaces provide a limited but very powerful alternative to multiple inheritance .[9] Classes in Java can inherit members from only a single superclass, but they can implement any number of interfaces. Objects that do not share the same class or superclass may still be members of the same type by virtue of implementing the same interface.


  

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