In this course you will discover the elements of the functional programming style and learn how to apply them usefully in your daily programming tasks, such as modeling business domains or implementing business logic. You will also develop a solid foundation for reasoning about functional programs, by touching upon proofs of invariants and the tracing of execution symbolically. 

The course is hands on; most units introduce short programs that serve as illustrations of important concepts and invite you to play with them, modifying and improving them. The course is complemented by a series programming projects as homework assignments.

Necessary preparation

• At least one year programming experience.
• Proficiency with Java or C#.
• Experience with C/C++, Python, Javascript or Ruby.
• You should have some familiarity using the command line.

The Program

1. Getting Started + Functions & Evaluation
   Get up and running with Scala on your computer. Complete an example assignment to familiarize yourself with our unique way of submitting assignments. In this week, you’ll learn the difference between functional imperative programming. You step through the basics of Scala; covering expressions, evaluation, conditionals, functions, and recursion.
2. Higher Order Functions
   This week, you’ll learn about functions as first-class values, and higher order functions. You’ll also learn about Scala’s syntax and how it’s formally defined. Finally, you’ll learn about methods, classes, and data abstraction through the design of a data structure for rational numbers.
3. Data and Abstraction
   This week, you’ll cover traits, and you’ll learn how to organize classes into hierarchies. You’ll cover the hierarchy of standard Scala types, and see how to organize classes and traits into packages. Finally, you’ll touch upon the different sorts of polymorphism in Scala.
4. Types and Pattern Matching
   This week you’ll learn about the relationship between functions and objects in Scala. You’ll zoom in on Scala’s type system, covering subtyping and generics, and moving on to more advanced aspects of Scala’s type system like variance. Finally, you’ll cover Scala’s most widely used data structure, Lists, and one of Scala’s most powerful tools, pattern matching.
5. Lists
   This week you dive into Lists, the most commonly-used data structure in Scala.
6. Collections
   After a deep-dive into Lists, this week you’ll explore other data structures; vectors, maps, ranges, arrays, and more. You’ll dive into Scala’s powerful and flexible for-comprehensions for querying data.

What will you learn

• Understand the principles of functional programming.
• Write purely functional programs, using recursion, pattern matching, and higher-order functions.
• Design immutable data structures.
• Combine functional programming with objects and classes.