r - How to add variable key/value pair to list object?

Question

I have two variables, key and value, and I want to add them as a key/value pair to a list:

key = "width"
value = 32

mylist = list()
mylist$key = value

The result is this:

mylist
# $key
# [1] 32

But I would like this instead:

mylist
# $width
# [1] 32

How can I do this?

Answer 1

R lists can be thought of as hashes- vectors of objects that can be accessed by name. Using this approach you can add a new entry to the list like so:

key <- "width"
value <- 32

mylist <- list()
mylist[[ key ]] <- value

Here we use the string stored in the variable key to access a position in the list much like using the value stored in a loop variable i to access a vector through:

vector[ i ]

The result is:

myList
$width
[1] 32