Regular expressions

Regular expressions are sequences of characters that define search patterns. Symbolic notation is used to find particular sequences of interest. Regular expressions are used in many different contexts including SQL queries, web scraping, and data wrangling. Chapter 8 covers regular expressions within R, but the syntax for pattern matching is identical across almost all platforms and programming languages. One thing to note is that to escape a metacharacter in R, two backslashes are needed. For example, \\d is the correct syntax to denote a digit.