Chapter 1, Tasting Functional Style in C#, introduces the functional programming approach by discussing its concepts and the comparison between functional and imperative programming. We also try to refactor a simple imperative code into a functional approach.

Chapter 2, Walkthrough Delegates, covers the definition, syntax, and use of delegates. We also discuss the variance of delegates and the built-in delegate.

Chapter 3, Expressing Anonymous Methods with Lambda Expressions, walks us through the concept of delegates and uses it to create and use an anonymous method. After we dig through the anonymous method, we can transform it into a lambda expression and then apply it to functional programming.

Chapter 4, Extending Object Functionality with Extension Methods, elaborates the benefits of using the extension method in functional programming. Before that, we discuss the use of the extension method and also discuss how to get this new method in IntelliSense. Also, we try to invoke the extension method from other assemblies.

Chapter 5, Querying Any Collection Easily with LINQ, enumerates the LINQ operator provided by C# and compares the two LINQ syntaxes: Fluent Syntax and Query Expression Syntax. We also discuss deferred execution in the LINQ process.

Chapter 6, Enhancing the Responsiveness of the Functional Program with Asynchronous Programming, covers asynchronous programming for the functional approach. It will explain the Asynchronous Programming Model and the Task-based Asynchronous pattern.

Chapter 7, Learning Recursion, explains the advantages of recursion over the loop sequence. We also discuss direct and indirect recursion in this chapter.

Chapter 8, Optimizing the Code Using Laziness and Caching Techniques, covers the technique used to optimize the code in the functional approach. We talk about laziness thinking and the caching technique in order to optimize our code.

Chapter 9, Working with Pattern, covers the advantages of using patterns compared to conventional switch-case operations. We discuss pattern matching and monad in this chapter. We use the pattern matching feature, which is the new feature provided by C# 7.

Chapter 10, Taking an Action in C# Functional Programming, walks us through developing functional code based on given imperative code. We use our learning in the previous chapter to create an application using the functional approach.

Chapter 11, Coding Best Practice and Testing the Functional Code, explains the best practice in the functional approach, including the creation of an honest signature and dealing with the side-effects. We also separate the code into domain logic and mutable shell and then test it using unit testing.