an abbreviated notation for creating a simple local object "in-line" within any expression, simply by wrapping the desired code in a " new " expression

an extension to the local class concept described above

a subclass of an existing class ( Base in this example) or an implementation of an interface

a subspecies of local class, and therefore mutually exclusive with member types

a local class that is declared and instantiated in a single statement, often as a parameter to a method

local class that has no name.