Swift Deinitialization

In Swift, deinitialization is the process of cleaning up an instance of a class or structure when it is no longer needed. Deinitializers are called automatically just before the instance is deallocated from memory. In contrast to initializers, Swift automatically provides a default deinitializer for classes that deallocates any resources that the instance has acquired.

Syntax

The syntax for a deinitializer is as follows:

1deinit {
2    // deinitialization code here
3}

The deinitializer does not take any parameters and is written with the deinit keyword.

Example

Here's an example of a simple Person class with a deinitializer that prints a message when the instance is deallocated:

1class Person {
2    var name: String
3    
4    init(name: String) {
5        self.name = name
6    }
7    
8    deinit {
9        print("\(name) is being deallocated")
10    }
11}
12
13// Create an instance of the class
14var person: Person? = Person(name: "Alice")
15
16// Deallocate the instance
17person = nil
18
19// Output: "Alice is being deallocated"

In the example, we create an instance of the Person class and then set it to nil, which triggers the deinitializer and prints a message to the console.