Closures.swift

import Foundation

// Closures

// Escaping closures vs Non Escaping closures
// Escaping closures escapes the function body

func doSomething(_ a: Int, completion: @escaping (Int) -> Void) {
    var a = a
    DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
        a += 10
        completion(a)
    }
    
    completion(a)
}


doSomething(2) { value in
    print(value)
}

func createSomething(_ a: Int, completion: ((Int) -> Void)?) {
    var a = a
    DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
        a += 10
        completion?(a)
    }
    
    completion?(a)
}

// Trailing closure
createSomething(2) { value in
    print(value)
}