How to use typealias to make it easier to use complex types
Swift version: 5.6
Although it’s generally a good idea to use structs or classes for defining your types, sometimes you’ll find yourself using tuples. If this happens to you, it’s quite tedious having to type the full definition of your tuple whenever you want to use it, so the typealias lets you create a specific name for it:
typealias Name = (first: String, last: String)Type aliases are also useful when you might want to change the underlying type used for data. For example, you might store a value as a Float today, but you want to leave open the option to switch to a Double later on. In this situation, you’d use typealias like this:
typealias MyValue = FloatYou can then go ahead and use MyValue everywhere in your code, and if you ever choose to change to Double you can just change the type alias and all your code will update.
SAVE 50% To celebrate WWDC23, all our books and bundles are half price, so you can take your Swift knowledge further without spending big! Get the Swift Power Pack to build your iOS career faster, get the Swift Platform Pack to builds apps for macOS, watchOS, and beyond, or get the Swift Plus Pack to learn advanced design patterns, testing skills, and more.
Available from iOS 8.0 – learn more in my book Pro Swift
Similar solutions…
- How to safely use reference types inside value types with isKnownUniquelyReferenced()
- How to fix the error “Expression was too complex to be solved in reasonable time”
- How to make a TextField expand vertically as the user types
- How to make custom types from strings using ExpressibleByStringLiteral
- How to use Codable to load and save custom data types
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
