# How to Count Number of Elements in List in R (With Example)

You can use the following methods to count the number of elements in a list in R:

Method 1: Count Number of Elements in List

`length(my_list)`

Method 2: Count Number of Elements in Specific Component of List

`length(my_list[[3]])`

Method 3: Count Number of Elements in Each Component of List

`lengths(my_list)`

The following examples show how to use each method in practice with the following list in R:

```#define list
my_list <- list(x=c(1, 4, 4, 5, 7, 8),
y='Hey',
z=factor(c('A', 'B', 'C', 'D')))

#view list
my_list

\$x
[1] 1 4 4 5 7 8

\$y
[1] "Hey"

\$z
[1] A B C D
Levels: A B C D
```

### Example 1: Count Number of Elements in List

We can use the length() function to simply count how many elements are in the list:

```#count number of elements in list
length(my_list)

[1] 3
```

We can see that there are 3 elements in the list.

### Example 2: Count Number of Elements in Specific Component of List

We can use the length() function combined with double brackets to count the number of elements in a  specific component of the list.

For example, we can use the following code to count how many elements are in the third component of the list:

```#count number of elements in third component of list
length(my_list[[3]])

[1] 4
```

We can see that there are 4 elements in the third component of the list.

Specifically, the four values are A, B, C, and D.

### Example 3: Count Number of Elements in Each Component of List

We can use the lengths() function to count the number of elements in each individual component of the list:

```#count number of elements in each component of list
lengths(my_list)

x y z
6 1 4
```

From the output we can see:

• x has 6 elements (1, 4, 4, 5, 7, 8)
• y has 1 element (‘hey’)
• z has 4 elements (‘A’, ‘B’, ‘C’, ‘D’)

Note that we could also use the sum() function with the length() function to count the total number of individual elements in the entire list:

```#count total number of individual elements in entire list
sum(lengths(my_list))

[1] 11 ```

We can see that there are 11 total elements in the entire list.

### Additional Resources

The following tutorials explain how to use other common functions in R: