Extract First & Last Word of Character String in R (3 Examples)

In this R tutorial you’ll learn how to get the first and last word of a character string.

The post is structured as follows:

Let’s get started:

Creation of Example Data

The following data will be used as a basis for this R programming language tutorial:

my_string <- "have a look at my very nice character string"  # Create example string
my_string                                                    # Print example string
# [1] "have a look at my very nice character string"

Have a look at the previous output of the RStudio console. It visualizes that our example data is a single character string containing multiple different words. These words a re separated by blanks.

Example 1: Get Last Word of Character String Using sub() Function

In this example, I’ll explain how to extract the very last word of a character string using the basic installation of the R programming language.

To accomplish this, we can apply the sub function as shown below:

my_string_last1 <- sub('^.* ([[:alnum:]]+)$', '\1',         # Extract last word
                       my_string)
my_string_last1                                              # Print last word
# [1] "string"

As you can see, the previous R code has printed the character string “string”, i.e. the last word of our input character string.

Example 2: Get Last Word of Character String Using word() Function of stringr Package

Example 2 shows how to use the stringr package to return the last word of a character string.

In order to use the functions of the stringr package, we first need to install and load stringr:

install.packages("stringr")                                  # Install & load stringr
library("stringr")

Next, we can apply the word() function of the stringr package:

my_string_last2 <- word(my_string, - 1)                      # Extract last word
my_string_last2                                              # Print last word
# [1] "string"

As you can see, the word() function has returned the same output as Base R in Example 1. However, the R syntax was much simpler.

Example 3: Get First Word of Character String Using word() Function of stringr Package

Similar to Example 2, we can use the word() function to find the first word of a character string.

Consider the R programming code below:

my_string_first <- word(my_string, 1)                        # Extract first word
my_string_first                                              # Print first word
# [1] "have"

The first word of our character string is “have”.

Video, Further Resources & Summary

Do you need further information on the R programming syntax of this article? Then I recommend having a look at the following video on my YouTube channel. I’m explaining the contents of this article in the video.

Furthermore, you may have a look at some of the related posts which I have published on this homepage. I have released numerous articles on topics such as extracting data, character strings, and numeric values already:

• Extract Numbers from Character String Vector
• Extract First or Last n Characters from String in R
• Extract First Entry from Character String Split
• Capitalize First Letter of Each Word in Character String
• All R Programming Examples

In summary: In this tutorial, I have demonstrated how to return the first and last word of a character string in the R programming language. Please let me know in the comments below, in case you have additional questions.