

class {base}                                 R Documentation

_O_b_j_e_c_t _C_l_a_s_s_e_s

_D_e_s_c_r_i_p_t_i_o_n_:

     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.

_U_s_a_g_e_:

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

_D_e_t_a_i_l_s_:

     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.

_S_e_e _A_l_s_o_:

     `UseMethod', `NextMethod'.

