The Java Tutorials ‘s lesson on regular expressions introduces Java’s support for regular expressions via the java.util.regex package and highlights the two classes Pattern and Matcher.

Fast track your regular expressions with the help of possessive quantifiers, independent grouping, lookarounds, and the regex pattern-matching engine itself.

Before you use regex, use other operators where possible (e.g., exact matches, contains). Test your regex against expected inputs and ensure that it’s matching what you expect.

Do you need an example of how to use Java's UnaryOperator in a functional Lambda expression? This tutorial shows you where when and how to use the UnaryOperator interface in a function.