What are the 5 concepts in re?

Answer 1

In the context of the R programming language, the re package primarily deals with regular expressions. The five key concepts include:

1. Patterns: The sequences of characters that define the search criteria.
2. Metacharacters: Special characters that have specific meanings in the context of regular expressions (e.g., ^, $, .).
3. Character Classes: Sets of characters that can match a single position in a string (e.g., [a-z], \d).
4. Quantifiers: Indicate the number of times a character or group should be matched (e.g., *, +, {n}).
5. Groups and Capturing: Parentheses are used to group patterns and capture matched substrings for further use.