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, you were introduced to regular expressions with a bit of history and their flavors. You learnt some use cases where regex are needed. Finally, we covered the basic rules and building blocks of writing regex, with a few examples. You also learnt the eager-matching behavior of the regex engine and how it may impact matching in alternations.

In the next chapter, we will go a level deeper and cover the core concepts of regex in detail, such as quantifiers, lazy vs greedy matching, anchors, negated character classes, Unicode and predefined character classes, special escape sequences, and the rules of escaping inside a character class.