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

The MatchResult interface

MatchResult is an interface for representing the result of a match operation. This interface is implemented by the Matcher class. This interface contains query methods used to determine the results of a match against a regular expression. The match boundaries, groups, and group boundaries can only be retrieved but not modified through this interface. Here is a list of important methods provided in this interface:

Method Name


int start()

Returns the start index of the match in the input

int start(int group)

Returns the start index of the specified capturing group

int end()

Returns the offset after the last character matched

int end(int group)

Returns the offset after the last character of the subsequence captured by the given group during this match

String group()

Returns the input substring matched by the previous match

String group(int group)

Returns the input subsequence captured by the given group during the previous match operation

int groupCount()

Returns the number...