In this chapter, we looked at how Xcode runs our playground and what a program can look like without the concept of functions. The concept of functions was introduced on a metaphorical level with tips on how one can visualize a function, with three common characteristics of a function being the following:
It can receive some input
It can be pure
It can return something
Further, we looked at different examples of functions written in Swift before creating our own function for simulating the task of creating a pizza.
In the next chapter, we will explore new and exciting concepts of programming, such as arrays and dictionaries, which are useful for storing our values in boxes.