Finding the length of vectors, factors, arrays, or lists is a common operation.

**Length in R**

To **get** the **length** of **vectors**, **lists**, **factors**, or other objects in R, use the **length()** method.

**Syntax**

`length(data)`

**Parameters**

The length() function accepts **data **as a required parameter that can be either vector, factor, list, or other objects.

**Return Value**

The length() function returns the size of an R object.

**Example**

```
rv <- 1:5
print("The length of the rv is: ")
print(length(rv))
```

**Output**

```
[1] "The length of the rv is: "
[1] 5
```

Here, we defined a vector that returns the length; otherwise, the length returns **NA**.

**How to Set Vector Length in R**

To set a vector length, use the assignment operator (<-) and assign the variable’s new length.

```
rv <- 1:5
print("The length of the rv is: ")
print(length(rv))
length(rv) <- 9
print("The new length of rv is: ")
print(length(rv))
```

**Output**

```
[1] "The length of the rv is: "
[1] 5
[1] "The new length of rv is: "
[1] 9
```

**How to find the length of list in R**

To **find** the **length** of the **list** in **R**, use the **length()** function. The **length()** function accepts a list as an argument and returns the length of the list.

```
rl <- list(c(1, 2, 3, 4))
print(rl)
print(length(rl))
```

**Output**

```
[[1]]
[1] 1 2 3 4
[1] 1
```

From the output, you can see that we did not get the length of each element of the list. It returns the number of entries on our list. If you want to get the length of a single list element, use the following code.

```
rl <- list(c(1, 2, 3, 4))
print(rl)
print(length(rl[[1]]))
```

**Output**

```
[[1]]
[1] 1 2 3 4
[1] 4
```

Now, you can see that the total element of the list is 4.

**How to find a length of String in R**

To **find** a length of a **string** in **R**, use the **nchar()** function. The **length()** function accepts a string as an argument and returns the length of the string.

```
str <- "Yello, by Homer Simpson"
nchar(str)
```

**Output**

`[1] 23`

The nchar() function can be used to get the length of a string.

You can also use the length() function, but the output will differ from the above.

```
str <- "Yello, by Homer Simpson"
length(str)
```

**Output**

`[1] 1`

**Conclusion**

**NULL** returns 0. Most other objects return length 1.

That is it for the length() function in R.

Krunal Lathiya is an Information Technology Engineer by education and web developer by profession. He has worked with many back-end platforms, including Node.js, PHP, and Python. In addition, Krunal has excellent knowledge of Data Science and Machine Learning, and he is an expert in R Language. Krunal has written many programming blogs, which showcases his vast expertise in this field.