Search icon
Arrow left icon
All Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Newsletters
Free Learning
Arrow right icon
Flutter Cookbook, Second Edition - Second Edition

You're reading from  Flutter Cookbook, Second Edition - Second Edition

Product type Book
Published in May 2023
Publisher Packt
ISBN-13 9781803245430
Pages 712 pages
Edition 2nd Edition
Languages
Author (1):
Simone Alessandria Simone Alessandria
Profile icon Simone Alessandria

Table of Contents (19) Chapters

Preface 1. Getting Started with Flutter 2. Creating Your First Flutter App 3. Dart: A Language You Already Know 4. Introduction to Widgets 5. Mastering Layout and Taming the Widget Tree 6. Adding Interactivity and Navigation to Your App 7. Basic State Management 8. The Future is Now: Introduction to Asynchronous Programming 9. Data Persistence and Communicating with the Internet 10. Advanced State Management with Streams 11. Using Flutter Packages 12. Adding Animations to Your App 13. Using Firebase 14. Firebase Machine Learning 15. Flutter Web and Desktop 16. Distributing Your Mobile App 17. Other Books You May Enjoy
18. Index

Introducing Dart Null Safety

When Dart version 2.12 was shipped in Flutter in March 2021, an important language feature was added that impacts how you should view null values for your variables, parameters, and fields: this is sound null safety.

Generally speaking, variables that have no value are null, and this may lead to errors in your code. If you have been programming for any length of time, you are probably already familiar with null exceptions in your code. The goal of null safety is to help you prevent execution errors raised by the improper use of null.

With null safety, by default, your variables cannot be assigned a null value.

There are obviously cases when you want to use null, but you have to explicitly allow null values in your apps. In this recipe, you will see how to use null safety to your advantage, and how to avoid null safety errors in your code.

Getting ready

Create a new Pad in DartPad.

How to do it...

Let’s see an example...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at €14.99/month. Cancel anytime}