Key Concepts

Review core concepts you need to learn to master this subject

Defining an Enumeration

Switch Statements

CaseIterable

Raw Values

Associated Values

Instance Methods

Computed Properties

Defining an Enumeration

enum Day {
  case monday
  case tuesday
  case wednesday
  case thursday
  case friday
  case saturday
  case sunday
}

let casualWorkday: Day = .friday

Enumerations (or enums) are used to define a new custom type with a list of possible cases. When creating an instance of an enumeration, its value must be one of the cases.

Enumerations
Lesson 1 of 1
  1. 1
    Introducing Enumerations
    With some forms of information, we know all of the possible values that can exist. Let’s say you’re building a transportation app. Users can either travel by truck, plane, or boat. We could just …
    Start
  2. 2
    What is an Enumeration?
    Enumerations are a data type found in many popular programming languages, but Swift extends their functionality, offering capabilities one would typically expect to find only in classes. In Swift, …
    Start
  3. 3
    Using Enumerations in a Switch Control Flow
    A switch statement is a common place you might want to use an enum. Switch statements must be exhaustive. This means that each possible case must be addressed explicitly by the control flow. Using …
    Start
  4. 4
    Iterating Over Enumeration Cases
    Enumerations aren’t technically one of the three primary collection types offered by Swift (Arrays, Sets, and Dictionaries). However, they do define a set of cases, and you may find yourself in a s…
    Start
  5. 5
    Defining Raw Values for Enumeration Cases
    In some other programming languages, enumerations are built using another underlying type. For example, in C++, enumerations are actually a set of integers. The Swift implementation of enumeratio…
    Start
  6. 6
    Using Associated Values with Enumerations
    One of the powerful functionalities Swift adds to enums is the ability to store an associated value of any type attached to a case value. This is different from raw values because each case can hav…
    Start
  7. 7
    Implementing Methods in Enumerations
    In Swift, enumerations are truly first-class types and have several advanced capabilities. One of those capabilities is the ability to define instance methods inside of an enumeration. One such u…
    Start
  8. 8
    Implementing a Computed Property in an Enumeration
    Another amazing functionality Swift gives with enumerations is the ability to incorporate computed properties. A computed property is a property that isn’t directly stored but is instead derived fr…
    Start
  9. 9
    Reviewing What We Learned
    Great job 🙌 We have learned about the power and flexibility offered by Swift enumerations. Here’s what we covered: * What an enumeration is * How to use enumerations in a switch control flow * Ho…
    Start

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