You can use the following syntax to create an empty list in R:

#create empty list with length of zero empty_list <- list() #create empty list of length 10 empty_list <- vector(mode='list', length=10)

The following examples show how to use these functions in practice.

**Example 1: Create Empty List in R with Length of Zero**

The following code shows how to create an empty list with a length of zero in R:

#create empty list empty_list <- list() #verify that empty_list is of class 'list' class(empty_list) [1] "list" #view length of list length(empty_list) [1] 0

The result is a list with a length of 0.

**Example 2: Create Empty List in R with Specific Length**

The following code shows how to create an empty list of length 8 in R:

#create empty list of length 8 empty_list <- vector(mode='list', length=8) #verify that empty_list is of class 'list' class(empty_list) [1] "list" #view list empty_list [[1]] NULL [[2]] NULL [[3]] NULL [[4]] NULL [[5]] NULL [[6]] NULL [[7]] NULL [[8]] NULL

The result is a list with a length of 8 in which every element in the list is NULL.

**Example 3: Append Values to Empty List in R**

One of the most common reasons to create an empty list is to then fill it with values using a loop.

The following code shows how to create an empty list, then fill it with values:

#create empty list of length 8 empty_list <- vector(mode='list', length=8) #get length of list len <- length(empty_list) #define values to append to list new <- c(3, 5, 12, 14, 17, 18, 18, 20) #fill values in list i = 1 while(i <= length(new)) { empty_list[[i]] <- new[i] i <- i + 1 } #display updated list empty_list [[1]] [1] 3 [[2]] [1] 5 [[3]] [1] 12 [[4]] [1] 14 [[5]] [1] 17 [[6]] [1] 18 [[7]] [1] 18 [[8]] [1] 20

Notice that the empty list is now filled with the new values that we specified.

**Additional Resources**

How to Create an Empty Data Frame in R

How to Append Values to List in R

How to Convert List to Vector in R