Every operation in R is a function call. For example, when you subset a vector using []
, you’re really calling the function [
.
y = 1:6
y[2]
## [1] 2
`[`(y, 2)
## [1] 2
This allows us to easily subset the elements of a list when the elements are vectors. For example, given a list of 3 elements: a character vector, an integer vector, and a logical vector, we can use lapply
and [
to easily extract the 2nd value from each vector.
x = list(letters[1:4], 1:5, c(T, F, T, F, F, T))
lapply(x, `[`, 2)
## [[1]]
## [1] "b"
##
## [[2]]
## [1] 2
##
## [[3]]
## [1] FALSE