Final

• The final keyword is used to indicate that a class, method, or property cannot be overridden or subclassed
• Declaring a class as final, it means that it’s the end of the inheritance chain for that class, and it cannot be subclassed further.

final class LastClass {
		// Class definition
}

// error! PleaseNot class cannot inherit from a 'final' class 'LastClass'
class PleaseNot: LastClass {

}

Beneficial

• Preventing Subclassing
  • final ensures that its functionality remains intact and cannot be altered by subclasses
• Performance Optimization
  • The compiler can perform certain optimizations on final classes and methods because it knows they cannot be overridden

Dispatch

• Grand Central Dispatch(GCD)
• Execute code concurrently on multicore hardware by submitting work to dispatch queues managed by the system

참조

https://gurjit-singh.medium.com/what-is-final-class-in-swift-53a0246f6abd