Why does class() return not the same inside Map()?-CodePudding

Reading about R types I came across this answer where class() is used inside of Map. Now I wonder why class() returns something else if used inside Map(). See here:

# Using class() without Map()
> class(matrix())
[1] "matrix" "array"

# Using class() within Map()
Map(function(x){class(x)}, matrix())
[[1]]
[1] "logical"

Why is this happening?

EDIT

Inferred from comment and answer: To obtain the expected, i.e. same output, we need to use

Map(function(x){class(x)}, list(matrix()))
[[1]]
[1] "matrix" "array"

CodePudding user response：

You apply (map) all elements of an empty matrix to a function returning it's class. The class of an empty thing is NA. A vector only containing NAs is of class logical in R.