Languages such as Java and C# generally refer to the error handling process as exception handling; within the Swift documentation, Apple refers to this process as error handling. While, externally, Java and C# exception handling may look very similar to Swift's error handling, there are some significant differences that those familiar with exception handling in the other languages will notice throughout this chapter.
Before we can really understand how error handling works in Swift, we must first see how we would represent an error. In Swift, errors are represented by values of types that conform to the Error protocol. Swift's enumerations are very well suited to modeling error conditions because, generally, we have a finite number of error conditions to represent.
Let's look at how we would use an enumeration to represent an error. For this, we will define a fictitious error named MyError with three error conditions: Minor, Bad, and Terrible:
enum MyError...