Delegates vs Closures: An Intro to Swift Programming

Delegates vs Closures: An Intro to Swift Programming

Swift is a great programming language for iOS developers. It’s fast, powerful, and easy to learn. One of the most important concepts in Swift is the use of delegates and closures. In this article, we’ll explore the differences between delegates and closures and how they can be used in Swift programming.

Delegates are a type of object-oriented programming pattern that allows one object to send messages to another object. In Swift, delegates are used to communicate between objects. They are often used as callbacks, allowing one object to respond to changes in another object.

Closures are blocks of code that can be executed at any time. In Swift, closures are used to create functions that can be passed around like variables. Closures can be used to create reusable code that can be used in many different contexts.

The biggest difference between delegates and closures is that delegates are objects while closures are functions. Delegates can store data and respond to messages from other objects. Closures, on the other hand, are self-contained pieces of code that can be executed at any time.

Let’s look at a simple example of using delegates and closures in Swift. First, let’s create a class called `MyViewController` that will act as the delegate for our closure. This class will define a function called `didUpdateData` that will be called when the data is updated.

class MyViewController: UIViewController {

    func didUpdateData() {
        // do something when the data is updated
    }
}

Now, let’s create a closure that will be used to update the data. This closure will take a parameter called `updatedData` and will call the `didUpdateData` function of the `MyViewController` class.

let updateDataClosure = { (updatedData: Any) in
    let viewController = MyViewController()
    viewController.didUpdateData()
}

We can now call the `updateDataClosure` whenever we need to update the data. This is an example of how delegates and closures can be used in Swift programming.

In conclusion, delegates and closures are two powerful tools that can be used in Swift programming. Delegates are objects that can store data and respond to messages from other objects. Closures are blocks of code that can be executed at any time. By understanding the differences between delegates and closures, developers can create more powerful and flexible applications.