Classes Plantarum ('Classes of plants', Leiden, Oct. 1738) is a book that was written by Carl Linnaeus, a Swedish botanist, physician, zoologist and naturalist.

1. <programming> The prototype for an object in an object-oriented language; analogous to a derived type in a procedural language. A class may also be considered to be a set of objects which share a common structure and behaviour. The structure of a class is determined by the {class variables} which represent the state of an object of that class and the behaviour is given by a set of methods associated with the class. Classes are related in a class hierarchy. One class may be a specialisation (a "subclass") of another (one of its "superclasses") or it may be composed of other classes or it may use other classes in a client-server relationship. A class may be an abstract class or a concrete class. See also signature. 2. <programming> See type class. 3. <networking> One of three types of Internet addresses distinguished by their most significant bits. 3. <language> A language developed by the Andrew Project. It was one of the first attempts to add object-oriented features to C. (1995-05-01)