Regular expressions are one of these topics that computer-friendly folks can easily spend more time on than anyone must know. Consult the following links for additional resources on regular expressions.
For a proper definition, the historical background, and key references on regular expressions:
E.4.2 Learning and training
Many online sites offer tutorials and ways of trying out your regex skills:
?base::regexin R provides documentation on Regular Expressions as used in R.
[70_regex.Rmd updated on 2020-07-07 13:13:33 by hn.]
Wickham, H. (2019a). stringr: Simple, consistent wrappers for common string operations. Retrieved from https://CRAN.R-project.org/package=stringr