Variables and Objects
Like most computer languages, R uses variables as a means of storing
information in memory and retrieving it later. Variables can be
assigned to using the <- or = operator. For example, to assign the
number 5 to the variable foo, you would write
> foo <- 5
Variables can retrieved simply by referring to them by name. For
example, to add 8 to the variable foo and store the result in
bar, you would do the following:
> bar <- foo + 8
In R, variables are more correctly called objects, because they have structure and do not directly refer to a specific memory location.
Basic Types
Vectors
A vector is the major data type used in R. You can think of it as a line of cells, each containing a value of the same type. [Type here means a number or a string.]