Key Concepts

Review core concepts you need to learn to master this subject

Swift Class

Instance of a Class

Class Properties

init() Method

Inheritance

Overriding

Reference Types

Swift Class

// Using data types:
class Student {
  var name: String
  var year: Int
  var gpa: Double
  var honors: Bool
}


// Using default property values:
class Student {
  var name = ""
  var year = 0
  var gpa = 0.0
  var honors = false
}

A class is used to programmatically represent a real-life object in code. Classes are defined by the keyword class followed by the class name and curly braces that store the class’s properties and methods.

Classes
Lesson 1 of 1
  1. 1
    Introduction to Classes
    So far, we’ve used several data types, including Int, Double, String, and Bool. We’ve even created our own “type” using structs to make blueprints and templates for objects in our program. Besides…
    Start
  2. 2
    Creating a Class
    Just like structures, we can use classes to model everyday objects. And the syntax looks awfully similar. Here’s the basic syntax for creating a class: class Name { } The class keyword follo…
    Start
  3. 3
    Creating an Instance
    To refresh, a class is simply a template to create objects. The term “object” is often used to refer to an instance of a class. So for example, a building blueprint is a class and each house is an …
    Start
  4. 4
    The Init Method
    In the previous exercise, we’ve supplied our instances’ properties with default values. However, if we know that our class instances vary a lot from one to another, we can include an init() method …
    Start
  5. 5
    Inheritance
    In the previous exercises, we’ve defined a class, created instances, and added an init() method. But all these concepts were the same in structures. So now we have to ask, “how are classes differen…
    Start
  6. 6
    Overriding Methods
    To continue the conversation on inheritance, a subclass can provide its own custom implementation of a property or method that is inherited from a superclass. This is known as overriding. To ove…
    Start
  7. 7
    Classes are Reference Types
    Another one of the biggest main distinctions between structures and classes is that: - Structures are value types - Classes are reference types A value type is a type whose value is copied when i…
    Start
  8. 8
    Review
    Woohoo! You’ve now added classes to your Swift toolbox. 🙌 With structures and classes being so darn similar, when do we use structures and when do we use classes? The rule of thumb is to always …
    Start

What you'll create

Portfolio projects that showcase your new skills

Pro Logo

How you'll master it

Stress-test your knowledge with quizzes that help commit syntax to memory

Pro Logo