NEW: Join my free 100 Days of SwiftUI challenge today! >>

What are static methods and variables?

Swift version: 5.1

Paul Hudson    @twostraws   

Static methods and variables belong to the type that defined them, rather than instances of that type. For example, we could create a struct to track taxis in a city, like this:

struct Taxi1 {
    var ownerName: String
    var licensePlate: String
}

Each instance of that struct will have its own ownerName and licensePlate property strings. However, if we made a static property inside that struct then it would be shared by all taxis. For example, we could add this property to store how many taxis exist in the city:

struct Taxi2 {
    var ownerName: String
    var licensePlate: String
    static var count: Int = 0
}

When we want to reference that property we need to use Taxi2.count, because it belongs to the struct not to instances of that struct.

The same is true of static methods, which are sometimes called “type methods” – they belong to the struct or class that defined them rather than instance of the class. In practice that means you can’t use self inside the method because there is no instance to refer to.

LEARN SWIFTUI FOR FREE I have a massive, free SwiftUI video collection on YouTube teaching you how to build complete apps with SwiftUI – check it out!

Available from iOS 8.0

Similar solutions…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

BUY OUR BOOKS
Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!

Average rating: 5.0/5