Regular Expressions (abbreviated as REGEX, also known as “Grep”)" are a mini-language pattern-matching used by many computer languages (R, python), and programmes (OpenOffice/LibreOffice, RStudio “find” function).
We’ll use regular expressions through the tidyverse/stringr functions
str_subset (returns the matching strings) and
str_whichReturns the indexes of matching elements
str_countReturns how many times the pattern matches
str_locate_allReturns start and end position of matches
str_extractReturns the matching part of the string