str_locate & str_locate_all Functions in R (2 Examples)

In this R tutorial you’ll learn how to use str_locate and str_locate_all to locate the position of patterns in a character string.

Table of contents:

• Example Data
• Example 1: Application of str_locate Function in R
• Example 2: Application of str_locate_all Function in R
• Video & Further Resources

With that, here’s the step-by-step process.

Example Data

As a first step, we have to create an exemplifying character string in R:

x <- c("my example string")       # Create character string

In addition, we have to install and load the stringr package of the tidyverse to R:

install.packages("stringr")       # Install stringr package
library("stringr")                # Load stringr package

Example 1: Application of str_locate Function in R

In Example 1, I’ll show you how to apply the str_locate function. Have a look at the following R code:

str_locate(x, "mple")             # Apply str_locate function
#      start end
# [1,]     7  10

As you can see, the str_locate command returns a matrix containing a starting and an ending value. In this example, the pattern “mple” begins at the 7th character and ends at the 10th character of our string.

Example 2: Application of str_locate_all Function in R

The str_locate function, which I have explained in Example 1, returns only the first occurrence of a certain pattern. If we want to extract all locations of such a pattern, we need to use the str_locate_all function:

str_locate_all(x, "m")            # Apply str_locate_all function
# [[1]]
#      start end
# [1,]     1   1
# [2,]     7   7

As you can see based on the previous output, the letter “m” occurs at the first and at the 7th position of our character string.

Video & Further Resources

Have a look at the following video tutorial of my YouTube channel. I’m explaining the R programming syntax of this tutorial in the video:

The YouTube video will be added soon.

Furthermore, you may read the other tutorials on https://statisticsglobe.com/:

• R Functions List (+ Examples)
• The R Programming Language

To summarize: This article explained how to identify the positioning of certain characters in a string in R. In case you have any additional questions and/or comments, please tell me about it in the comments. Furthermore, please subscribe to my email newsletter in order to get updates on the newest articles.