Stringr

Overview

Stringr is the main string manipulation package in tidyverse.

Stringr focusses on the most important and comonly used string manipulation functions. It is based on stringi which has a comprehensive set of functions.

stringr homepage

This website aims to quickly cover some of the stringr functions and uses. Therefore, there are a lot more stringr functions than covered here. Please check the below link for the full list.

Full stringr reference page

If you are unfamiliar with strings please see:

String chapter in R for Data Science 2e

Sections

There are many sections for stringr. These are summarised below.

Viewing strings

  • str_view(): View the raw contents of a string.
    • Includes information about various special characters and how to escape them with \.

Character manipulation

These functions allow you to manipulate strings in vectors.

  • str_length(): Determine the length of a string (i.e. count the number of characters in a string).
  • str_sub(): Extract or modify a substring using a start and end position.
  • str_dup(): Duplicate a string a specified number of times.

Combining strings

These functions allow you combine strings into one scalar or vector.

  • str_c(): Combine strings together (similar to paste0()).
  • str_flatten(): Flatten a vector of strings into one string.
  • str_glue(): Similar to str_c() but allows you to include variables within the strings to combine.
    • Variable names are included in the strings with curly braces like so: {variable_name}

White space tools

These functions allow you to add, remove, and manipulate whitespaces (e.g. spaces and tabs).

  • str_pad(): Add padding characters to strings shorter than a specified length. The padded strings will all have a length equal to the length.
  • str_trim(): Remove all white spaces from the start and end of strings.

Pattern matching

These functions allow you to carry out various tasks with regular expressions.

  • str_subset(): Subset vector to elements that match a pattern/regular expression.
  • str_detect(): Return logical vector showing which elements match (TRUE) a pattern/regular expression or not (FALSE).
  • str_count(): Count number of matches to a pattern/regular expression.

For an introduction to regular expressions please see: