In the previous two lessons, you learned the fundamentals of Swift syntax, data types, and how to use variables to store data in a Swift program. With knowledge of these language elements, you're already prepared to create fully functional Swift programs.

In this lesson, you'll build on these skills, and learn how to develop fully featured Swift applications, catch unexpected errors, and begin using asynchronous programming paradigms. You'll learn how to create your own data types, and create object-oriented applications using classes and structs.

All object-oriented programming languages provide the ability to build your own custom classes. Classes increase the level of modularity in your application, and promote code reuse. This lesson will cover the key skills you'll need to build robust, object-oriented applications with Swift.