ModifiersAccess Control for Methods and VariablesStatic Variables and MethodsFinal Classes, Methods, and VariablesVariablesMethodsClassesAbstract Classes and MethodsPackagesThe import DeclarationClass Name ConflictsCreating Your Own PackagesPicking a Package NameCreating the Folder StructureAdding a Class to a PackagePackages and Class Access ControlInterfacesThe Problem of Single InheritanceInterfaces and ClassesImplementing and Using InterfacesImplementing Multiple InterfacesOther Uses of InterfacesCreating and Extending InterfacesNew InterfacesMethods Inside InterfacesExtending InterfacesCreating an Online StorefrontSummaryQ&AQuizQuestionsAnswersCertification PracticeExercises