Quickly familiarize yourself with regular expressions in Java and learn how to use them in various use-cases related to string manipulation.

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Regular expressions describe a pattern of characters used for searching a string. They are very useful for parsing information like dates, phone numbers, or zip codes from important text files such as code files, log files, spreadsheets, or documents. 

Below are the most common use cases of regular expressions: 
- Data validation of data fields or values like phone numbers, zip codes, email addresses, etc.
- Information extraction from text files for further processing
- Pattern matching of strings or textual information
- Search and replace operation on texts

This course will teach you how to perform pattern matching with a regular expression using a Java API for these practical use cases.

Tarun Telang

Tarun Telang is a passionate software engineer, leader, architect, author, and active contributor in various online technical forums.

Java Expert & Enterprise Software Architect

Mastering Regular Expressions in Java


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* Regular expressions are powerful tools for string pattern matching, search-and-replace, and text processing tasks.
* The dot (`.`) character will match any single character.
* A pair of square brackets `[]` represent character class.
* A character class matches the single character enclosed within the square brackets.
* A dash (`-`) character specifies character ranges. For example, `[a-z]` represents all the lowercase characters in the English language.
* Character classes can be negated and can combine different regular expressions using subtraction, union, and intersection operations.

* The backslash (`\`) symbol is a metacharacter used to represent  various predefined character classes.
* `\s` will match any whitespace (space, tab, carriage-return etc.).
* `\d` matches digits (`0` to `9`).
* The symbols `?`, `*`, `+` are used as quantifiers.
* `X?` matches zero or one occurrence of `X`.
* `X*` matches zero or more occurrences of `X`
* `X+` matches one or more occurrences of `X`
* Regular expressions in Java can be implemented with the `Pattern` and `Matcher` classes.
* In Java, many  methods of the `String` class support regular expressions.

* The `split()` method splits the string around matches of the given regular expression.

Let's now summarise all the concepts learned so far. 

Summary

Let's now summarise all the concepts learned so far.

Introduction

Java Regex APIs

Building Blocks of Regular Expressions

Course Wrap Up

Summary

Summary