<- 3
aa <- 3L
bb <- "3"
cc <- "TRUE"
dd <- TRUE
ee <- "NA"
ff <- NA gg
Data types
Creating objects
First, let’s create some objects:
aa <- 3; bb <- 3L; cc <- "3"; dd <- "TRUE"; ee <- TRUE; ff <- "NA"; gg <- NA
Checking data types
Guess what data type each object is then check it.
typeof(aa)
[1] "double"
typeof(bb)
[1] "integer"
typeof(cc)
[1] "character"
typeof(dd)
[1] "character"
typeof(ee)
[1] "logical"
typeof(ff)
[1] "character"
typeof(gg)
[1] "logical"
How do we test if aa
is an integer?
is.integer(aa)
[1] FALSE
What will is.logical(dd)
return?
is.logical(dd)
[1] FALSE
How do we test if ff
and gg
are NA
?
is.na(ff)
[1] FALSE
is.na(gg)
[1] TRUE
Checking if objects are the same
Are aa
and bb
the same? How do we test this?
aa
[1] 3
bb
[1] 3
== bb aa
[1] TRUE
What about aa
and cc
?
aa
[1] 3
cc
[1] "3"
== cc aa
[1] TRUE
A safer comparison tool is identical()
. Test if aa
and bb
are identical. Then try aa
and cc
.
identical(aa, bb)
[1] FALSE
identical(aa, cc)
[1] FALSE
Now see if aa
is identical to 3
and if bb
is identical to 3L
.
identical(aa, 3)
[1] TRUE
identical(bb, 3L)
[1] TRUE