The integer class
Numeric format is the default number system. If you explicitly want an integer, you need to specify it with the L suffix.
When using the combine function, integer must be also specified with the suffix L
> v=c(1L,3L,-5L)
> str(v)
int [1:3] 1 3 -5
> v <- c(1L)
> class(v)
[1] "integer"
With the sequence operator
> v=5:10
> str(v)
int [1:6] 5 6 7 8 9 10