Book Image

Java 9 Regular Expressions

By : Anubhava Srivastava
Book Image

Java 9 Regular Expressions

By: Anubhava Srivastava

Overview of this book

Regular expressions are a powerful tool in the programmer's toolbox and allow pattern matching. They are also used for manipulating text and data. This book will provide you with the know-how (and practical examples) to solve real-world problems using regex in Java. You will begin by discovering what regular expressions are and how they work with Java. This easy-to-follow guide is a great place from which to familiarize yourself with the core concepts of regular expressions and to master its implementation with the features of Java 9. You will learn how to match, extract, and transform text by matching specific words, characters, and patterns. You will learn when and where to apply the methods for finding patterns in digits, letters, Unicode characters, and string literals. Going forward, you will learn to use zero-length assertions and lookarounds, parsing the source code, and processing the log files. Finally, you will master tips, tricks, and best practices in regex with Java.
Table of Contents (15 chapters)
Title page
About the Author
About the Reviewer
Customer Feedback
Free Chapter
Getting Started with Regular Expressions


In this chapter, we learned zero-width assertions and how they are crucial for solving some important matching problems. We discussed the boundary matcher, \G, and its usefulness in solving some problems. We discovered the idea behind atomic groups and understood how they can improve the overall regex performance. Then, we covered all the important lookahead and lookbehind patterns. We covered some interesting matching, validation, and splitting problems that are solved using lookarounds.

In the next chapter, we will continue to learn advanced concepts of Java regular expressions, such as union and intersection within character classes, and negated character classes.