tgnivekucn

	func B(callback: @escaping (Bool) -> Void) {
		//step2
		DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + 100) {//this 100s indicates long time task
			//step 3
			callback(true)
		}	
	}

	//step1
	func B {

tgnivekucn

//ex: 比較 a,b大小
var a = 54
var b = 5
//用function:
func compare(val1: Int,val2: Int) -> Bool {
 return a > b
}
assert(compare(val1:a,val2:b), "error, a can not larger than b")
//用closure:
assert(a > b, "error, a can not larger than b") //note: a > b 即為closure,其省略了參數和回傳值

tgnivekucn

//用語言提供的基本語法
func test1(arr: [Int]) -> Void {
 for item in arr {
 if isOdd(val: item) {
 print("\(item)")
 }
 }
}
func test2(arr: [Int]) -> Void {
 for item in arr {

tgnivekucn

//用語言提供的基本語法找出陣列中的奇數和偶數
func test1(arr: [Int]) -> Void {
    for item in arr {
        if isOdd(val: item) {
            print("\(item)")
        }
    }
}
func test2(arr: [Int]) -> Void {
    for item in arr {

tgnivekucn

import UIKit
import Combine

class ViewModel {
    var updateLabel: ((String?) -> Void)?
    var textString: String? {
        didSet {
            updateLabel?(textString)
        }
    }

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// lazy Singleton: create the singleton object when needed
// Note: Global constants and variables are always computed lazily
// ref: https://docs.swift.org/swift-book/LanguageGuide/Properties.html#ID263
class SingletonGreed {
    static let shared = SingletonGreed()
    private init() {}
}

class SingletonThreadSafe {
    private static var shared: SingletonThreadSafe?

tgnivekucn

// Product and Concrete Product
protocol Adventurer {
    func getType() -> String
}

class Archer: Adventurer {
    func getType() -> String {
        print("I'm an archer")
        return String(describing: Archer.self)
    }

tgnivekucn

// Product and Concrete Product
protocol Adventurer {
    func getType() -> String
}

class Archer: Adventurer {
    func getType() -> String {
        print("I'm an archer")
        return String(describing: Archer.self)
    }

tgnivekucn

Color identifier naming rule:
Regular expression:
(color)\.((common)|([A-Za-z])+(Page)){1}(\.([A-Za-z])+)*(\.([A-Za-z])+(Color)s?)$

Example:
1. Color category
2. UI page name or plist file name
3. Subview name(ex: customCell) (p.s. this field might be zero)
4. Unique color name (p.s. or unique color array name)
    

tgnivekucn

func validatePhoneNumber(phoneNumber: String) -> Bool {
    if let regex = try? NSRegularExpression(pattern: "09\\d{2}-\\d{3}-\\d{3}") {
        let range = NSRange(location: 0, length: phoneNumber.utf16.count)
        let result = regex.firstMatch(in: phoneNumber, range: range)
        if result != nil {
            return true
        }
    }
    return false
}