In Chapter 1, you wrote your first F# program. I broke it down to give you a feel for what you were doing, but much of the code is still a mystery. In this chapter, I provide the necessary foundation for you to understand that code fully, but more importantly, I present several more examples that you can use to grasp the basics of F# before you move on to the more complex features.

The first section of this chapter covers primitive types, like int and string, which are the building blocks for all F# programs. I then cover functions so you can manipulate data.

The fourth section details foundational types such as list, option, and unit. Mastering these types enables you to expand into the object-oriented and functional styles of F# code covered in later chapters.