Data types

Creating objects

First, let’s create some objects:

aa <- 3; bb <- 3L; cc <- "3"; dd <- "TRUE"; ee <- TRUE; ff <- "NA"; gg <- NA

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

aa == bb

[1] TRUE

What about aa and cc?

aa

[1] 3

cc

[1] "3"

aa == cc

[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