getClass {methods} | R Documentation |
Get the definition of a class.
getClass(Class, .Force = FALSE, where) getClassDef(Class, where, package)
Class |
the character-string name of the class. |
.Force |
if TRUE , return NULL if the class is
undefined; otherwise, an undefined class results in an error. |
where |
environment from which to begin the search for the definition; by default, start at the top-level (global) environment and proceed through the search list. |
package |
the name of the package asserted to hold the
definition. Supplied instead of where , with the
distinction that the package need not be currently attached. |
A call to getClass
returns the complete definition of the class
supplied as a string, including all slots, etc. in classes that this
class extends. A call to getClassDef
returns the definition of
the class from the environment where
, unadorned. It's usually getClass
you want.
If you really want to know whether a class is formally
defined, call isClass
.
The object defining the class. This is an object of class
classRepresentation
. However, do not deal
with the contents of the object directly unless you are very sure you
know what you're doing. Even then, it is nearly always better
practice to use functions such as setClass
and
setIs
. Messing up a class object will cause great
confusion.
Chambers, John M. (2008) Software for Data Analysis: Programming with R Springer. (For the R version.)
Chambers, John M. (1998) Programming with Data Springer (For the original S4 version.)
getClass("numeric") ## a built in class cld <- getClass("thisIsAnUndefinedClass", .Force = TRUE) cld ## a NULL prototype ## If you are really curious: utils::str(cld) ## Whereas these generate errors: try(getClass("thisIsAnUndefinedClass")) try(getClassDef("thisIsAnUndefinedClass"))