# What is head() Function in R

The head() function in R is “used to display the first n rows in the input data frame”.

## Syntax

``head(x, n = number)``

## Parameters

1. x: It is an input dataset / dataframe.
2. n: It is the number of rows that the function should display.

## Return value

The head() function returns an object like the input object.

## Example 1: The head() function with data frame

Let’s get the first three rows of the data frame using the head() function.

``````df <- data.frame(c1 = c("a", "b", "c", "d"),
c2 = c("e", "f", "g", "h"),
c3 = c("i", "j", "k", "l"),
c4 = c("m", "n", "o", "p"),
c5 = c("q", "r", "s", "t"))

df
cat("First three rows of data frame", "\n")

Output

``````   c1 c2 c3 c4 c5
1  a  e  i  m  q
2  b  f  j  n  r
3  c  g  k  o  s
4  d  h  l  p  t
First three rows of data frame
c1 c2 c3 c4 c5
1  a  e  i  m  q
2  b  f  j  n  r
3  c  g  k  o  s``````

## Example 2: The head() function with vector

Applying the head() function to a Vector will return the number of elements equal to the n parameter of the head() function.

``````rv <- 1:10
rv
cat("First five integers of vector", "\n")

Output

`````` 1 2 3 4 5 6 7 8 9 10
First five integers of vector
 1 2 3 4 5``````

## Example 3: The head() function with matrix

Let’s create a matrix of 5 X 3 and fetch the first 3 rows of the Matrix using the head() function.

``````rv <- 1:15
mtrx <- matrix(rv, nrow = 5, ncol = 3)
mtrx
cat("Using head() function to get first 3 rows", "\n")

Output

``````     [,1] [,2] [,3]
[1,]  1    6    11
[2,]  2    7    12
[3,]  3    8    13
[4,]  4    9    14
[5,]  5   10    15
Using head() function to get first 3 rows
[,1] [,2] [,3]
[1,]  1    6    11
[2,]  2    7    12
[3,]  3    8    13
``````

## Example 4: The head() function with dataset

We will import the USArrests inbuilt R dataset and use that dataset’s head() function.

``df <- datasets::USArrests``

Use the head() function to get the first five rows of the dataset.

``````df <- datasets::USArrests
``````           Murder Assault UrbanPop  Rape