Java SE RegEx

This exam tests knowledge of the Java implementation of regular expressions (RegEx). The focus is on writing and interpreting RegEx patterns, not the specifics and peculiarities of the Matcher and Pattern classes. Matchers and Patterns may appear in code snippets, but the details of these classes are out of scope.

The exam is not about throwing hugely complex patterns at you and expecting you to perform as a human Matcher.

The best and clearest RegEx reference is Mastering Regular Expressions (3rd edition) by Jeffrey Friedl, which includes a chapter on Java's RegEx implementation.

A more compact but less exhaustive reference is the Regular Expressions section of the Essential Classes trail on the Java Tutorials site. A handy quick reference is the JavaDocs for the java.util.regex.Pattern class.

	Released	Beta	Frozen
Special Characters 2 questions Describe the purpose of metacharacters. Place backslashes, tabs, line-feeds and carriage-returns into patterns. Interpret patterns containing these metacharacters: ^, $, ?, *, + Use metacharacters as literal characters in patterns (escaping).	14	85	25	Add a question Beta questions
Character Classes 2 questions Explain what a character class is. Use appropriate metacharacters to implement negation (^), ranges (-), unions (nested classes), intersections/subtractions (&&). Name and use the predefined character classes: ., \d, \D, \s, \S, \w, \W. (Out of scope: POSIX character classes, `java.lang.Character` classes, Classes for Unicode blocks and categories)	17	80	10	Add a question Beta questions
Boundary Matchers 2 questions Employ these boundary matchers in patterns: \b, \B, \A, \G, \Z, \z.	12	19	15	Add a question Beta questions
Quantifiers 2 questions Explain the differences between greedy, reluctant and possessive quantifiers. Recognise which parts of a pattern request greedy, reluctant or possessive searches.	18	20	18	Add a question Beta questions
Grouping 2 questions Create "sub-patterns" within a pattern using grouping. Know how capturing groups are numbered; identify a capturing group by its number. Explain the difference between capturing and non-capturing groups. (Out of scope: back references)	12	14	19	Add a question Beta questions