You can use the **unlist() **function in R to quickly convert a list to a vector.

This function uses the following basic syntax:

unlist(x)

where:

**x**: The name of an R object

The following examples show how to use this function in different scenarios.

**Example 1: Use unlist() to Convert List to Vector**

Suppose we have the following list in R:

#create list my_list <- list(A = c(1, 2, 3), B = c(4, 5), C = 6) #display list my_list $A [1] 1 2 3 $B [1] 4 5 $C [1] 6

The following code shows how to convert a list to a vector using the **unlist()** function:

#convert list to vector new_vector <- unlist(my_list) #display vector new_vector A1 A2 A3 B1 B2 C 1 2 3 4 5 6

Note that you can specify **use.names = FALSE** to remove the names from the vector:

#convert list to vector new_vector <- unlist(my_list, use.names = FALSE) #display vector new_vector [1] 1 2 3 4 5 6

**Example 2: Use unlist() to Convert List to Matrix**

The following code shows how to use **unlist()** to convert a list to a matrix:

#create list my_list <- list(1:3, 4:6, 7:9, 10:12, 13:15) #convert list to matrix matrix(unlist(my_list), ncol=3, byrow=TRUE) [,1] [,2] [,3] [1,] 1 2 3 [2,] 4 5 6 [3,] 7 8 9 [4,] 10 11 12 [5,] 13 14 15

The result is a matrix with five rows and three columns.

**Example 3: Use unlist() to Sort Values in List**

Suppose we have the following list in R:

#create list some_list <- list(c(4, 3, 7), 2, c(5, 12, 19)) #view list some_list [[1]] [1] 4 3 7 [[2]] [1] 2 [[3]] [1] 5 12 19

Now suppose we attempt to sort the values in the list:

#attempt to sort the values in the list sort(some_list) Error in sort.int(x, na.last = na.last, decreasing = decreasing, ...) : 'x' must be atomic

We receive an error because the list must first be converted to a vector for us to sort the values.

We can use the following **unlist()** function to sort the values:

#sort values in list sort(unlist(some_list)) [1] 2 3 4 5 7 12 19

Notice that we’re able to successfully sort the list of values without any error because we first used **unlist()**, which converted the list to a numeric vector.

**Additional Resources**

The following tutorials explain how to perform other common operations in R:

How to Use length() Function in R

How to Use cat() Function in R

How to Use substring() Function in R