The [ operator can be used to extract multiple elements from a list. The syntax is similar to how you would extract a single element, but you instead pass a vector of indices to the [ operator.
For example, the following code would extract the first and third elements of the list x:
x <- list(foo = 1:4, bar = 0.6, baz = "hello")
x[c(1, 3)]
This code would return a list with two elements: the first element of the list x and the third element of the list x.
It's important to note that the [ operator and the [[ operator are not the same. The [[ operator is used to extract a single element from a list, while the [ operator can be used to extract multiple elements from a list.
The [[ operator also returns the element itself, while the [ operator returns a list with the extracted elements.
