
Object-Oriented Programming in R 87
Slots:
Name: y
Class: numeric
> removeClass("Ohno")
[1] TRUE
> tryCatch(getClass("Ohno"), error = function(x) "Ohno is gone")
[1] "Ohno is gone"
3.4.1.1 Introspection
Once a class has been defined, there are a number of software tools that
can be used to find out about that class. These include getSlots that will
report the slot names and types, the function slotNames that will report only
the slot names. These functions are demonstrated using the class A defined
ab ove.
> getSlots("A")
s1
"numeric"
> slotNames("A")
[1] "s1"
The class itself can be retrieved using getClass.The function extends can
b e called with either the name ...