Swift version: 5.1
Swift has two anonymous types:
AnyObject. They are subtly different, and you will need to use both sooner or later.
AnyObject refers to any instance of a class, and is equivalent to
id in Objective-C. It’s useful when you specifically want to work with a reference type, because it won’t allow any of Swift’s structs or enums to be used.
AnyObject is also used when you want to restrict a protocol so that it can be used only with classes.
Any refers to any instance of a class, struct, or enum – literally anything at all. You’ll see this in Swift wherever types are unknown or are mixed in ways that can be meaningfully categorized:
let values: [Any] = [1, 2, "Fish"]
Ideally you should avoid both
AnyObject in your code – it’s better to be more specific if you can be.
SAVE 20% ON iOS CONF SG The largest iOS conference in Southeast Asia is back in Singapore for the 5th time in January 2020, now with two days of workshops plus two days of talks on SwiftUI, Combine, GraphQL, and more! Save a massive 20% on your tickets by clicking on this link.
Available from iOS 8.0 – learn more in my book Swift Design Patterns
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.