What are closures in Swift and how do they relate to scope?

What are closures in Swift and how do they relate to scope?

Closures in Swift are self-contained blocks of functionality that can be passed around and used in your code. They capture and store references to variables and constants from their surrounding context, which is known as scope.

Can you give me an example of a closure in Swift?

Sure! Here's a simple example:

let greeting = { (name: String) in
    print("Hello, \(name)!")
}

greeting("Alice") // Output: Hello, Alice!

How do closures capture values from their surrounding context?

Closures capture values by storing references to the variables and constants from their surrounding context. This means that even if the original variables go out of scope, the closure can still access those values.

What are escaping and non-escaping closures?

Escaping closures are those that are called after the function they were passed to returns, while non-escaping closures are called within the function. Non-escaping closures can capture values directly, while escaping closures require special handling.