R has several preloaded data packages that can be very helpful in learning R.
The available packages can be loaded by using the command data(), which will
then bring up a menu with options.
To exit that menu, type q. To list what data is currently loaded, use the
ls() command with empty parentheses. The following example loads the
Orange data set (regarding the growth of orange trees).
> data(Orange)
The commands head(), tail(), and rm() can be used similarly to how they
would be in a Unix environment.
To show the first line of the Orange dataset, the command would be
head(Orange, n=1). If you wanted to unload the Orange dataset ,
use rm(Orange).