

   OObbjjeecctt CCllaasssseess

        class(x)
        class(x) <- names
        unclass(x)
        inherits(x, name)

   DDeessccrriippttiioonn::

        R possesses a simple generic function mechanism which
        can be used for an object-oriented style of program-
        ming.  Method despatch takes place based on the class
        of the first argument to the generic function.

        An R ``object'' is a data object which has a `class'
        attribute.  A class attribute is a vector of character
        strings giving the names of the classes which the
        object ``inherits'' from.  When a generic function
        `fun' is applied to an object with class attribute
        `c("first", "second")', the system searches for a func-
        tion called `fun.first' and, if it finds it, applies it
        to the object.  If no such function is found, a func-
        tion called `fun.second' is tried.  If no class name
        produces a suitable function, the function
        `fun.default' is used.

        The function `class' prints the vector of names of
        classes an object inherits from.  Correspondingly,
        `class<-' sets the classes an object inherits from.

        `unclass' returns (a copy of) its argument with its
        class information removed.

        `inherits' indicates whether its first argument inher-
        its from a class with name equal to its second argu-
        ment.

   SSeeee AAllssoo::

        `UseMethod', `NextMethod'.

