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 discussed composite and inner character classes. We found out how we can use the union, intersection, and subtraction operations to combine simple character classes and make a completely different character class to suit our requirements. You learned some good usage patterns of composite character classes for solving tricky problems. Note how we could avoid more complex lookahead and lookbehind assertions by using the union and intersection of character classes.

In the next chapter, we will discuss the pitfalls of some poorly written regular expressions, and you will learn ways to avoid them. You will also learn some important optimizing tips and performance improvement methods for writing complex regular expressions.