class(x) class(x) <- names unclass(x) inherits(x, name)
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 function called
fun.first and, if it finds it, applies it to the object. If no
such function is found, a function 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 inherits from a
class with name equal to its second argument.
UseMethod, NextMethod.