What is a selector?
Swift version: 5.6
Selectors are effectively the names of methods on an object or struct, and they are used to execute some code at runtime. They were common in Objective-C, but the earliest versions of Swift didn't include some core selector functionality so their use declined for a while. That functionality (things like performSelector(inBackground:)) has since been restored.
In Swift, selectors are most commonly found when working with the target/action paradigm that you find in classes such as Timer and UIBarButtonItem. For example, when you create a timer you need to tell it who to notify when the timer fires (the target) and what selector should be called (the action). The same goes for bar button items: when the button is tapped, what selector should be called, and on what object?
SPONSORED Build Chat messaging quickly with Stream Chat. The Stream iOS Chat SDK is highly flexible, customizable, and crazy optimized for performance. Take advantage of this top-notch developer experience, get started for free today!
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 7.0
Similar solutions…
- How to fix “argument of #selector refers to instance method that is not exposed to Objective-C”
- How to cancel a delayed perform() call
- How to use UIKeyCommand to add keyboard shortcuts
- How to add a bar button to a navigation bar
- How to adjust a UIScrollView to fit the keyboard
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
