Final classes
Although class inheritance is very useful – and in fact large parts of Apple’s platforms require you to use it – sometimes you want to disallow other developers from building their own class based on yours.
Swift gives us a final keyword just for this purpose: when you declare a class as being final, no other class can inherit from it. This means they can’t override your methods in order to change your behavior – they need to use your class the way it was written.
To make a class final just put the final keyword before it, like this:
final class Dog {
var name: String
var breed: String
init(name: String, breed: String) {
self.name = name
self.breed = breed
}
}
SPONSORED Catch bugs as soon as they happen and know exactly why a crash occurred. Instabug's SDK grabs all the logs they need to fix bugs, crashes and performance issues in minutes instead of days. Get screenshots, device details, network logs, repro steps, and tons of other critical insights needed to resolve issues and prioritize product backlogs straight from your dashboard. It only takes a minute to integrate!
Sponsor Hacking with Swift and reach the world's largest Swift community!
