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/*

One of the first things someone new to iOS Development finds is that dealing with the keyboard is trickier
than they think it should be. Simply changing the scrolling extents of a UITableView (or UIScrollView, or 
UICollectionView) that is partially covered by they keyboard reveals a lot about the internals of how iOS
works and highlights various "gotchas" that need to be considered.

There are various ways to know that a keyboard has been shown - but observing some specific notifications
provides a reliable way to allow you to modify your views to deal with it.

xuanvinhtd

Đinh nghĩa capture list như ví dụ sau:

lazy var someClosure: (Int, String) -> String = {
    [unowned self, weak delegate = self.delegate!] (index: Int, stringToProcess: String) -> String in
   // closure body goes here
}

Nếu một closure không có tham số thì ta có thể mô tả đơn giản như thế này:

lazy var someClosure: () -> String = {

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class HTMLElement {

   let name: String
   let text: String?
 
   lazy var asHTML: () -> String = {
       [unowned self] in
       if let text = self.text {
           return "<\(self.name)>\(text)</\(self.name)>"
       } else {

xuanvinhtd

class HTMLElement {

   let name: String
   let text: String?

   lazy var asHTML: () -> String = {
       if let text = self.text {
           return "<\(self.name)>\(text)</\(self.name)>"
       } else {
           return "<\(self.name) />"

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class Country {

   let name: String
   var capitalCity: City!

   init(name: String, capitalName: String) {
       self.name = name
       self.capitalCity = City(name: capitalName, country: self)
   }
}

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class Customer {

   let name: String
   var card: CreditCard?

   init(name: String) {
       self.name = name
   }
   deinit { print("\(name) is being deinitialized") }
}

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var john: Person?

var unit4A: Apartment?



john = Person(name: "John Appleseed")

unit4A = Apartment(unit: "4A")

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class Person {

   let name: String

   init(name: String) { self.name = name }

   var apartment: Apartment?

   deinit { print("\(name) is being deinitialized") }

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class Person {


   let name: String


   init(name: String) { self.name = name }


   var apartment: Apartment?

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class Car {

   let name: String

   init(name: String) {

       self.name = name

       print("\(name) is being initialized")