Functional programming

1. Functional programming in Swift: Introduction

Before you dive in to the first article in this course, I want to give you a brief overview of our goals, how the content is structured, as well as a rough idea of what you can expect to find.

2. Building with pure functions

If I were to boil functional programming down to just two rules, the first one would be this: prefer to write pure functions as often as you can. What are pure functions, and why would you want them? Let’s start by exploring that in detail…

3. Functions as first-class types

If I were to boil functional programming down to just two rules, the second rule would be this: functions are first-class types, and should be passed around like any other kind of data. In this article we’re going to explore what that means, and what power it unleashes…

4. Transforming data with map()

In this article we’re going to look at the map() function, which transforms one thing into another thing. Along the way we’ll also be exploring some core concepts of functional programming, so if you read no other articles in this course at least read this one!

5. Applying a predicate with contains() and filter()

In this article we’re going to look at the contains() and filter() functions, which search a sequence to see whether a certain test passes. Along the way you’ll see how similar these two functions are, along with how to build them yourself.

6. Transforming data with compactMap()

In this article we’re going to look at the compactMap() function, which is a more advanced form of map() that adds an important second step to handle optional results. Please make sure you’ve already gone through my tutorial on map() before continuing here!

7. Condensing data down to a single value with reduce()

In this article we’re going to look at the reduce() function, which allows us to boil down multiple values to a single value as a way of summing up or summarizing a sequence.