This beginner's book aims to introduce you to the field of agile software development with C#. While there are numerous books on both C# and agile methodologies, few teach them together in a single package. This book will help you understand how agile blurs the lines between the roles of analyst, designer, programmer, and tester.

By combining C# and agile in one book, this guide allows you to experience all roles through a single journey. At the end of the book, you will find several small C# projects to work on, following agile principles. Collaborating with four or five other readers (e.g., in a college setting) will further benefit your understanding.

Please note that this book is not a reference and content will be kept at a minimum. Additionally, it is designed to cater to beginners and is not an in-depth coverage of any specific topic. If you require further details, readers are encouraged to research the web.

To maximize your learning experience, this book requires you to type all code, and we do not provide sample code downloads. We understand your time is valuable, but we believe hands-on practice is the best way to learn.

Throughout the book, you will be given plenty of exercises under the titles of "Programming Challenge" and "Test Your Understanding." We strongly encourage you to try all exercises as you work through the book.

Finally, this fourth edition of the book uses Visual Studio 2022 Community as the development environment.

Last but not least, we thank Dr. Youlong Zhuang for reviewing this fourth edition and providing valuable suggestions.