You can use the following basic syntax to create a list of lists in R:
#define lists
list1 #create list of lists
list_of_lists The following example shows how to use this syntax in practice.
Example: Create List of Lists in R
The following code shows how to create a list that contains 3 lists in R:
#define lists
list1 #create list of lists
list_of_lists #view the list of lists
list_of_lists
[[1]]
[[1]]$a
[1] 5
[[1]]$b
[1] 3
[[2]]
[[2]]$c
[1] "A"
[[2]]$d
[1] "B" "C"
[[3]]
[[3]]$e
[1] 20 5 8 16 We can then use single brackets [ ] to access a specific list.
For example, we can use the following syntax to access the second list:
#access second list
list_of_lists[2]
[[1]]
[[1]]$c
[1] "A"
[[1]]$d
[1] "B" "C" We can also use double brackets [[ ]] and the dollar sign operator $ to access a specific element within a specific list.
For example, we can use the following syntax to access element d within the second list:
#access element 'd' within second list
list_of_lists[[2]]$d
[1] "B" "C"
You can use similar syntax to access any element within any list.
Additional Resources
The following tutorials explain how to perform other common tasks with lists in R:
How to Convert a List to a Data Frame in R
How to Append Values to List in R