Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
C# Programming Cookbook

You're reading from   C# Programming Cookbook Quick fixes to your common C# programming problems, with a focus on C# 6.0

Arrow left icon
Product type Paperback
Published in Jul 2016
Publisher Packt
ISBN-13 9781786467300
Length 476 pages
Edition 1st Edition
Languages
Arrow right icon
Author (1):
Arrow left icon
Dirk Strauss Dirk Strauss
Author Profile Icon Dirk Strauss
Dirk Strauss
Arrow right icon
View More author details
Toc

Table of Contents (15) Chapters Close

Preface 1. New Features in C# 6.0 FREE CHAPTER 2. Classes and Generics 3. Object-Oriented Programming in C# 4. Composing Event-Based Programs Using Reactive Extensions 5. Create Microservices on Azure Service Fabric 6. Making Apps Responsive with Asynchronous Programming 7. High Performance Programming Using Parallel and Multithreading in C# 8. Code Contracts 9. Regular Expressions 10. Choosing and Using a Source Control Strategy 11. Creating a Mobile Application in Visual Studio 12. Writing Secure Code and Debugging in Visual Studio 13. Creating a Web Application in Azure Index

Creating code contract invariant


Something that is defined as invariant tells us that it will never change. It will always be the same, no matter what. This brings up a vast array of use cases if we consider this in the context of code contracts. The invariant code contract is basically used to validate the internal state of a class. So, what do we mean by the "internal state?" Well, the properties of the class give that class a specific state. Let's assume that we wanted to guarantee that the properties of the class we are using only accept specific values, thereby assuring the internal state of that class. This is where the code contract invariant comes into play.

Getting ready

You can understand the use of the invariant better with the use of the following example. Assume that the class needs to store dates. We can't ever store a date in the past though. Any date used in the class must be a current or future date.

How to do it…

  1. Before you go on, ensure that you have added the code contracts...

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 $19.99/month. Cancel anytime