In the previous sections, we discussed how to create a new class as well as how to define a hierarchy of classes. We will now discuss four commands that are helpful when working with classes: the slotNames, getSlots, getClass, and slot commands. Each command is briefly discussed in turn, and it is assumed that the Ant, FemaleAnt, and WorkerAnt classes that are given in the previous section are defined in the current workspace.

The first command, the slotnames command, is used to list the data components of an object of some class. It returns the names of each component as a vector of characters:

> worker <- WorkerAnt(Position=c(1,2,3),Length=5.6)
> slotNames(worker)
[1] "Foraging"      "Alarm"         "Food"          "Length"       
[5] "Position"      "pA"            "pI"            "ActivityLevel"

The getSlots command is similar to the slotNames command. The difference is that the argument is a character variable which is the name of the class you want to investigate...