takawang

import UIKit

class ViewController: UIViewController {
  var touchCountTimer: Timer?
  var touchBeginTime: Double = 0
  let droneCollection = DroneCollectionController(fromJsonFile: "ring") // composition
  
  override func viewDidLoad() {
    super.viewDidLoad()
    

takawang

import UIKit

// Point definition for json object
class Point: Decodable {
  let x, y: Int
  let color: String
  
  // load all points from json file.
  //
  // ref: https://stackoverflow.com/a/50042872

takawang

import AVFoundation
import AVKit
import UIKit

class ViewController: UIViewController {
  @IBOutlet weak var lyricsLabel: UILabel!
  @IBOutlet weak var videoView: UIView!
  
  var player: AVPlayer?
  var timer: Timer?

takawang

Notes about Swift Book

Ch2. Playground

• Swift strings use double quotes instead of single quote!
• Reference: How to print double quotes inside “”?
  1. use backslash to escape
  2. use """ delimiter
  3. enhanced delimiters (swift 5)

takawang

if age < 20 {
	print("hello world")
}

takawang

while num < 10 {
	num = number +1
}

repeat {
	number = number +1
} while number < 10

takawang

for i in 1..10 {
	print("hello \(i)")
}

takawang

var number2 = 15
var number3 : Int
number2 = number3 // <-- error! wihtout value

takawang

var age: Int = 18
var age = 18 // type inference
var age // <-- error! neither type declaration nor initialized value.

takawang

var name = "Jamie"
var intro = "my name is \(name). hello world"