25 Swift Task

Posted on 2019-11-27 Edited on 2019-12-03 In swift

Present View Example

ViewController

import UIKit

class ViewController: UIViewController {
    
    let label = UILabel()
    let button = UIButton()
    
    var number = 0

    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = .random()
        
        setupLabel()
        setupButton()
    }
    
    func setupLabel() {
        label.frame.size = CGSize(width: view.frame.width, height: 100)
        label.center = view.center
        label.text = "\(number)"
        label.textColor = .random()
        label.textAlignment = .center
        label.font = UIFont(name: "Arial", size: 90)
      
        view.addSubview(label)
    }
    
    func setupButton() {
        button.frame = CGRect(x: 0, y: view.bounds.height - 200,
                              width: view.bounds.width, height: 100)
        button.setTitle("Go to Next View", for: .normal)
        button.setTitleColor(.random(), for: .normal)
        button.titleLabel?.font = UIFont(name: "Arial", size: 20)
        button.titleLabel?.lineBreakMode = NSLineBreakMode.byWordWrapping
        button.titleLabel?.textAlignment = NSTextAlignment.center
        button.addTarget(self, action: #selector(didTapButton(_:)), for: .touchUpInside)
      
        view.addSubview(button)
    }
    
    @objc
    func didTapButton(_ sender: UIButton) {
        let nextVC = NextViewController()
        nextVC.modalPresentationStyle = .fullScreen
        nextVC.modalTransitionStyle = .flipHorizontal
        
        number += 1
        present(nextVC, animated: true, completion: nil)
    }
    
}

NextViewController

import UIKit

class NextViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
      
        view.backgroundColor = .random()
        
        setupButton()
    }
    
    override func viewWillAppear(_ animated: Bool) {
        setupLabel()
    }
    
    func setupLabel() {
        let label = UILabel()
      
        guard let vc = presentingViewController as? ViewController else { return }
        
        label.frame.size = CGSize(width: view.frame.width, height: 100)
        label.center = view.center
        label.text = "\(vc.number)"
        label.textColor = .random()
        label.textAlignment = .center
        label.font = UIFont(name: "Arial", size: 90)
        
        view.addSubview(label)
    }
    
    func setupButton() {
        let button = UIButton()
      
        button.frame = CGRect(x: 0, y: view.bounds.height - 200, width: view.bounds.width, height: 100)
        button.setTitle("Back to Pervious View", for: .normal)
        button.setTitleColor(.random(), for: .normal)
        button.titleLabel?.font = UIFont(name: "Arial", size: 20)
        button.titleLabel?.lineBreakMode = NSLineBreakMode.byWordWrapping
        button.titleLabel?.textAlignment = NSTextAlignment.center
        button.addTarget(self, action: #selector(didTapButton(_:)), for: .touchUpInside)
      
        view.addSubview(button)
    }
    
    @objc
    func didTapButton(_ sender: UIButton) {
        guard let vc = presentingViewController as? ViewController else { return }
      
        vc.number += 1
        vc.label.text = "\(vc.number)"
        vc.label.textColor = .random()
        vc.button.setTitleColor(.random(), for: .normal)
        vc.view.backgroundColor = .random()
      
        dismiss(animated: true, completion: nil)
    }

}

After read these codes you might have a question about .random(), because UIColor has no random method. I’ll let you know how to bring random method in your project. It’ll make your app more colorful.

extension CGFloat {
    static func random() -> CGFloat {
        return CGFloat(arc4random()) / CGFloat(UInt32.max)
    }
}

extension UIColor {
    static func random() -> UIColor {
        return UIColor(red:   .random(),
                       green: .random(),
                       blue:  .random(),
                       alpha: 1.0)
    }
}

here is the result of these codes

22 Swift Task

Posted on 2019-11-25 Edited on 2019-12-03 In swift

func plusAllDigits(_ number: Int) -> Int {
    var sum = 0
    
    for digit in String(number) { sum += Int(String(digit))! }
    
    return sum
}

plusAllDigits(13413)
// 12
plusAllDigits(100000)
// 1

func isHarshad(_ number: Int) -> Bool {
    var sum = 0
    
    for digit in String(number) { sum += Int(String(digit))! }
    
    return number % sum == 0
}

isHarshad(9)
// true
isHarshad(777)
// true
isHarshad(123)
// false

21 Swift Task

Posted on 2019-11-25 Edited on 2019-12-03 In swift

func plusOne(to number: Int) -> Int { number * (number + 1) / 2 }

plusOne(to: 10)
// 55
plusOne(to: 100)
// 5050

func ifNumberHasThreeSixNinePrintAsteriskFromOne(to here: UInt) {
    
    for number in 1 ... here {
        let hasThreeSixNine = String(number).contains("3") || String(number).contains("6") || String(number).contains("9")
        
        if hasThreeSixNine { print("*", terminator: " ") } else { print(number, terminator: " ") }
    }
    print("")
}

ifNumberHasThreeSixNinePrintAsteriskFromOne(to: 10)
// 1 2 * 4 5 * 7 8 * 10 
ifNumberHasThreeSixNinePrintAsteriskFromOne(to: 23)
// 1 2 * 4 5 * 7 8 * 10 11 12 * 14 15 * 17 18 * 20 21 22 *

func getGreastCommonDivisorAndLeastCommonMultiple(firstNumber: Int, secondNumber: Int) -> Dictionary<String, Int> {
    
    var greastCommonDivisorAndLeastCommonMultiple = Dictionary<String, Int>()
    
    func getGreastCommonDivisor(_ m: Int, _ n: Int) -> Int {
        var a: Int = 0
        var b: Int = max(m, n)
        var r: Int = min(m, n)

        while r != 0 {
            a = b
            b = r
            r = a % b
        }
        
        return b
    }
    
    func getLeastCommonMultiple(_ m: Int, _ n: Int) -> Int {
        m * n / getGreastCommonDivisor(m, n)
    }
    
    greastCommonDivisorAndLeastCommonMultiple.updateValue(getGreastCommonDivisor(firstNumber, secondNumber), forKey: "Greatest Common Divisor")
    greastCommonDivisorAndLeastCommonMultiple.updateValue(getLeastCommonMultiple(firstNumber, secondNumber), forKey: "Least Common Multiple")
    
    return greastCommonDivisorAndLeastCommonMultiple
}

getGreastCommonDivisorAndLeastCommonMultiple(firstNumber: 140, secondNumber: 72)
// ["Greatest Common Divisor": 4, "Least Common Multiple": 2520]
getGreastCommonDivisorAndLeastCommonMultiple(firstNumber: 85, secondNumber: 500)
//["Greatest Common Divisor": 5, "Least Common Multiple": 8500]

19 Swift Task

Posted on 2019-11-19 Edited on 2019-12-03 In swift

Class

Make this picture to a class with inheritance

class Animal {
    var brain = true
    var legs: Int
    
    init(legs: Int) {
        self.legs = legs
    }
}

class Human: Animal {
    override init(legs: Int) {
        super.init(legs: legs)
    }
}

class Pet: Animal {
    var fleas: Int
    
    init(fleas: Int) {
        self.fleas = fleas
        super.init(legs: 4)
    }
}

class Dog: Pet {
    override init(fleas: Int) {
        super.init(fleas: fleas)
    }
}

class Cat: Pet {
    override init(fleas: Int) {
        super.init(fleas: fleas)
    }
}

let animal = Animal(legs: 0)
animal.brain
// ture
animal.legs
// 0

let human = Human(legs: 2)
human.brain
// true
human.legs
// 2

let pet = Pet(fleas: 0)
pet.brain
// true
pet.legs
// 4
pet.fleas
// 0

let dog = Dog(fleas: 8)
dog.brain
// true
dog.legs
// 4
dog.fleas
// 8

let cat = Cat(fleas: 4)
cat.brain
// true
cat.legs
// 4
cat.fleas
// 4

18 Swift Task

Posted on 2019-11-19 Edited on 2019-12-03 In swift

Class

class Dog {
    var name: String
    var age: Int
    var weight: Double
    var breed: String
    
    init(name: String, age: Int, weight: Double, breed: String) {
        self.name = name
        self.age = age
        self.weight = weight
        self.breed = breed
    }
    
    func bark(to someone: String) {
        print("Bark to \(someone)")
    }
    
    func eat(_ food: String) {
        print("Eat \(food)")
    }
}

var goldenRetriever = Dog(name: "Golden", age: 2, weight: 10.2, breed: "Golden Retriever")

goldenRetriever.bark(to: "theif")
goldenRetriever.eat("dog food")

class Student {
    var name: String
    var age: Int
    var school: String
    var grade: Int
    
    init(name: String, age: Int, school: String, grade: Int) {
        self.name = name
        self.age = age
        self.school = school
        self.grade = grade
    }
    
    func study(about subject: String) {
        print("Study about \(subject)")
    }
    
    func eat(_ food: String) {
        print("eat \(food)")
    }
    
    func sleep(for hour: Int) {
        hour == 1 ? print("sleep for an hour") : print("sleep for \(hour) hours")
    }
}

var soohanlee = Student(name: "Soohan Lee", age: 19, school: "JukJeon", grade: 3)

soohanlee.study(about: "Swift")
soohanlee.eat("Gukbap")
soohanlee.sleep(for: 1)

class Phone {
    var model: String
    var price: Int
    var haveFaceID: Bool
    
    init(model: String, price: Int, haveFaceID: Bool) {
        self.model = model
        self.price = price
        self.haveFaceID = haveFaceID
    }
    
    func call(to someone: String) {
        print("call to \(someone)")
    }
    
    func text(to someone: String) {
        print("text to \(someone)")
    }
}

let iPhone4 = Phone(model: "iPhone 4", price: 9900000, haveFaceID: false)
iPhone4.call(to: "Mom")
iPhone4.text(to: "Dad")

class coffee {
    var name: String
    var price: Int
    var origin: String
    
    init(name: String, price: Int, origin: String) {
        self.name = name
        self.price = price
        self.origin = origin
    }
}

let cafeLatte = coffee(name: "Cafe Latte", price: 3000, origin: "Ethiopia")

Make Caculator with class

class Calculator {
    private var value = 0.0
    
    func add(_ number: Double) { value += number }
    
    func subtract(_ number: Double) { value -= number }
    
    func multiply(_ number: Double) { value *= number }
    
    func divide(_ number: Double) { value /= number }
    
    func reset() { value = 0 }
    
    func getValue() -> Double { value }
}

let calculator = Calculator()

calculator.add(10)
calculator.getValue()
// 10

calculator.add(5)
calculator.getValue()
// 15

calculator.subtract(9)
calculator.getValue()
// 6

calculator.subtract(10)
calculator.getValue()
// -4

calculator.multiply(4)
calculator.getValue()
// -16

calculator.multiply(-10)
calculator.getValue()
// 160

calculator.divide(10)
calculator.getValue()
// 16

calculator.reset()
calculator.getValue()
// 0

Make some formulas with class

class Square {
    private var width: Double
    private var height: Double
    
    private var area: Double
    private var perimeter: Double
    
    init(width: Double) {
        self.width = width
        self.height = width
        
        area = width * height
        
        perimeter = 4 * width
    }
    
    func getArea() -> Double { area }
    func getPerimeter() -> Double { perimeter }
}

let square = Square(width: 13)
square.getArea()
// 169
square.getPerimeter()
//52

class Rectangle {
    private var width: Double
    private var height: Double
    
    private var area: Double
    private var perimeter: Double
    
    init(width: Double, height: Double) {
        self.width = width
        self.height = height
        
        area = width * height
        
        perimeter = (2 * width) + (2 * height)
    }
    
    func getArea() -> Double { area }
    func getPerimeter() -> Double { perimeter }
}

let rectangle = Rectangle(width: 5, height: 12)
rectangle.getArea()
// 60
rectangle.getPerimeter()
// 34

class Circle {
    private var radius: Double
    
    private var area: Double
    private var circumference: Double
    
    init(radius: Double) {
        self.radius = radius
        
        area = Double.pi * pow(radius, 2)
        
        circumference = 2 * Double.pi * radius
    }
    
    func getArea() -> Double { area }
    func getcircumference() -> Double { circumference }
}

let circle = Circle(radius: 6)
circle.getArea()
// 113.09733552923255
circle.getcircumference()
// 37.69911184307752

class Triangle {
    private var width: Double
    private var height: Double
    
    private var area: Double
    
    init(width: Double, height: Double) {
        self.width = width
        self.height = height
        
        area = width * height / 2
    }
    
    func getArea() -> Double { area }
}

let triangle = Triangle(width: 3, height: 14)
triangle.getArea()
// 21

class Trapezoid {
    private var upperWidth: Double
    private var lowerWidth: Double
    private var height: Double
    
    private var area: Double
    
    init(upperWidth: Double, lowerWidth: Double, height: Double) {
        self.upperWidth = upperWidth
        self.lowerWidth = lowerWidth
        self.height = height
        
        area = 0.5 * height * (upperWidth + lowerWidth)
    }
    
    func getArea() -> Double { area }
}

let trapezoid = Trapezoid(upperWidth: 3, lowerWidth: 2, height: 5)
trapezoid.getArea()
// 12.5

class Cube {
    private var width: Double
    private var height: Double
    private var depth: Double
    
    private var volume: Double
    
    init(width: Double) {
        self.width = width
        self.height = width
        self.depth = width
        
        volume = width * height * depth
    }
    
    func getVolume() -> Double { volume }
}

let cube = Cube(width: 7)
cube.getVolume()
// 343

class RectangularSolid {
    private var width: Double
    private var height: Double
    private var depth: Double
    
    private var volume: Double
    
    init(width: Double, height: Double, depth: Double) {
        self.width = width
        self.height = height
        self.depth = depth
        
        volume = width * height * depth
    }
    
    func getVolume() -> Double { volume }
}

let rectangularSolid = RectangularSolid(width: 3, height: 2, depth: 5)
rectangularSolid.getVolume()
// 30

class CircularCylinder {
    private var radius: Double
    private var height: Double
    
    private var volume: Double
    
    init(radius: Double, height: Double) {
        self.radius = radius
        self.height = height
        
        volume = Double.pi * pow(radius, 2) * height
    }
    
    func getVolume() -> Double { volume }
}

let circularCylinder = CircularCylinder(radius: 3, height: 6)
circularCylinder.getVolume()
// 169.64600329384882

class Sphere {
    private var radius: Double
    
    private var volume: Double
    
    init(radius: Double) {
        self.radius = radius
        
        volume = 4 / 3 * Double.pi * pow(radius, 3)
    }
    
    func getVolume() -> Double { volume }
}

let sphere = Sphere(radius: 2)
sphere.getVolume()
// 33.510321638291124

class Cone {
    private var height: Double
    private var radius: Double

    private var volume: Double
    
    init(height: Double, radius: Double) {
        self.height = height
        self.radius = radius
        
        volume = 1 / 3 * Double.pi * pow(radius, 2) * height
    }
    
    func getVolume() -> Double { volume }
}

let cone = Cone(height: 2, radius: 3)
cone.getVolume()
// 18.84955592153876

15 Swift Task

Posted on 2019-11-15 Edited on 2019-12-03 In swift

Closure

Optimize clousre

let someClosure: (String, String) -> Bool = { (s1: String, s2: String) -> Bool in
    let isAscending: Bool

    if s1 > s2 {
        isAscending = true
    } else {
        isAscending = false
    }

    return isAscending
}

let optimizedSomeClosure: (String, String) -> Bool = { $0 > $1 }

someClosure("apple", "banana")
// false
optimizedSomeClosure("apple", "banana")
// false

someClosure("banana", "apple")
// ture
optimizedSomeClosure("banana", "apple")
// ture

let otherClosure: ([Int]) -> Int = { (values: [Int]) -> Int in
    var count: Int = 0
    for _ in values {
        count += 1
    }
    return count
}

let optimizedOtherClosure: ([Int]) -> Int = { $0.count }

otherClosure([0, 1, 2, 3, 4])
optimizedOtherClosure([0, 1, 2, 3, 4])

otherClosure([0])
optimizedOtherClosure([0])

These functions might seem work differently but short form of closures are just optimized so they return same value.

14 Swift Task

Posted on 2019-11-14 Edited on 2019-12-03 In swift

Optional, Enum

Combine Optional Strings and return a non Optional String

func combineStrings(str1: String?, str2: String?, str3: String?) -> String {
    (str1 ?? "") + (str2 ?? "") + (str3 ?? "")
}

combineStrings(str1: "AB", str2: "CD", str3: "EF")
// "ABCDEF"

Calculate using enumeration

enum Arithmetic {
    case addition, subtraction, multiplication, division
    
    func calculate(_ firstNumber: Double, _ secondNumber: Double) -> Double {
        switch self {
        case .addition:
            return firstNumber + secondNumber
        case .subtraction:
            return firstNumber - secondNumber
        case .multiplication:
            return firstNumber * secondNumber
        case .division:
            return firstNumber / secondNumber
        }
    }
}

Arithmetic.addition.calculate(10, 5)
// 15

Arithmetic.subtraction.calculate(10, 5)
// 5

Arithmetic.multiplication.calculate(10, 5)
// 50

Arithmetic.division.calculate(10, 5)
// 2

Convert celcius to fahrenheit and kelvin using enumertaion

enum Temperature {
    case celcius(Double), fahrenheit(Double), kelvin(Double)
    
    func toCelcius() -> Double {
        switch self {
        case .celcius(let celcius):
            return celcius
        case .fahrenheit(let fahrenheit):
            return (fahrenheit - 32) * 5 / 9
        case .kelvin(let kelvin):
            return kelvin + 273
        }
    }
}

Temperature.celcius(100).toCelcius()
// 100

Temperature.fahrenheit(100).toCelcius()
// 37.77777777777778

Temperature.kelvin(100).toCelcius()
// 373

Calculate using enumeration and recursive call

indirect enum ArithmeticExpression {
  case number(Int)
  case addition(ArithmeticExpression, ArithmeticExpression)
  case multiplication(ArithmeticExpression, ArithmeticExpression)
}

let five = ArithmeticExpression.number(5)
let four = ArithmeticExpression.number(4)
let sum = ArithmeticExpression.addition(five, four)
let product = ArithmeticExpression.multiplication(sum, ArithmeticExpression.number(2))

func evaluate(_ expression: ArithmeticExpression) -> Int {
    switch expression {
    case .number(let number):
        return number
    case .addition(let firstNumber, let secondNumber):
        return evaluate(firstNumber) + evaluate(secondNumber)
    case .multiplication(let firstNumber, let secondNumber):
        return evaluate(firstNumber) * evaluate(secondNumber)
    }
}

evaluate(five)
// 5

evaluate(sum)
// 9

evaluate(product)
// 18

13 Swift Task

Posted on 2019-11-13 Edited on 2019-12-03 In swift

Collection Types (Array, Dictionary, Set)

Return the array of people that has “E” in their favorite fruits

let appleLeadershipAndTheirFavoriteFruits = [
					     "Steve Jobs"        : "Apple",
                                             "Steve Wozniak"     : "Pineapple",
                                             "Jonathan Ive"      : "Kiwi",
                                             "Philip W. Schiller": "Mango",
                                             "Craig Federighi"   : "Fig",
                                             "Chris Lattner"     : "Avocado",
                                             "Jeff Williams"     : "Raspberry",
                                            ]

func getlistOfHasE(in list: Dictionary<String, String>) -> Array<String> {
    var listOfPeopleHasEInTheirFavoriteFruit = Array<String>()
    
    for (person, fruit) in list {
        let hasE = fruit.lowercased().contains("e") ? true : false
      	
        if hasE {
            listOfPeopleHasEInTheirFavoriteFruit.append(person)
        }
    }
    
    return listOfPeopleHasEInTheirFavoriteFruit
}

getlistOfHasE(in: appleLeadershipAndTheirFavoriteFruits)
// ["Steve Jobs", "Steve Wozniak", "Jeff Williams"]

Sort the array odd numbers go to forward and even numbers go to Backward

func oddGoToForwardEvenGoToBackward(numbers: Array<Int>) -> Array<Int> {
    var odds = Array<Int>()
    var evens = Array<Int>()
    
    for number in numbers {
        let isOdd = number % 2 == 1 ? true : false
        
        isOdd ? odds.append(number) : evens.append(number)
    }
    
    return odds + evens
}

oddGoToForwardEvenGoToBackward(numbers: [2, 8, 7, 1, 4, 3])
// [7, 1, 3, 2, 8, 4]

Print how many digit numbers are in array

func howManyNumbers(in numbers: Array<Int>) {
    var numberCounts = Dictionary<Int, Int>()
    var countedNumbers = Array<Int>()
    
    for i in 0 ... 9 {
        numberCounts[i] = 0
    }
    
    for number in numbers {
        for compareNumber in 0 ... 9 {
            if number == compareNumber {
                numberCounts[number]! += 1
                
                if !countedNumbers.contains(number) { countedNumbers.append(number) }
            }
        }
    }
    
    var result = String()
    
    for countedNumber in countedNumbers {
        result += "Number \(countedNumber) : Counts \(numberCounts[countedNumber]!), "
    }
    
    result = String(result.dropLast(2))
    
    print(result)
}

howManyNumbers(in: [1, 3, 3, 3, 8])
// "Number 1 : Counts 1, Number 3 : Counts 3, Number 8 : Counts 1"

Reverse a number

func reverseNumber(of number: Int) -> Int {
    var reversedNumber = String()
    
    for chr in String(number).reversed() {
        reversedNumber += String(chr)
    }
    
    return Int(reversedNumber)!
}

reverseNumber(of: 123)
// 321

reverseNumber(of: 400000)
// 4

Determine the number has unique digits or not

func isUniqueDigit(number: Int) -> Bool {
    var characterArray = Array<Character>()
    
    for chr in String(number) {
        characterArray.append(chr)
    }
    
    return characterArray.count == Array(Set(characterArray)).count
}

isUniqueDigit(number: 123456789)
// ture

isUniqueDigit(number: 111111111)
//false

Determine the array has unique letters or not

func getUniqueLetters(from letter: Array<String>) -> Array<String> {
    var uniqueLetters = Array<String>()
    
    for i in letter {
        var count = 0
        
        for j in letter {
            if i == j {
                count += 1
            }
        }
        
        if count == 1 {
            uniqueLetters.append(i)
        }
    }
    
    return uniqueLetters
}

getUniqueLetters(from: ["a", "b", "c", "a", "e", "d", "c"])
// ["b", "e", "d"]

Organize a carnivores phylogeny

let livingThings = [
    "Carnivores": [
        "Canidae": [
            "Canini": [
                "Canina",
                "Cerdocyonina",
            ],
            "Urocyon": [
                "Urocyon littoralis",
                "Urocyon cinereroargenteus",
            ],
        ],
        "Felidae": [
            "Pantherinae": [
                "Neofelis",
                "Panthera",
            ],
            "Felinae": [
                "Pardofelis",
                "Catopuma",
            ],
        ],
    ],
]

print(livingThings["Carnivores"]!["Felidae"]!["Felinae"]!)
// ["Pardofelis", "Catopuma"]

11 Swift Task

Posted on 2019-11-12 Edited on 2019-12-03 In swift

Get two natural number and combine them into one number

func stickTwoNaturalNumbers(firstNumber: Int, secondNumber: Int) -> Int {
    Int(String(firstNumber) + String(secondNumber))!
}

stickTwoNaturalNumbers(firstNumber: 12, secondNumber: 34)
// 1234

Compare two strings are the same or not

func isSameLetter(firstLetter: String, secondLetter: String) -> Bool {
    firstLetter == secondLetter
}

isSameLetter(firstLetter: "a", secondLetter: "a")
// true

isSameLetter(firstLetter: "a", secondLetter: "b")
// false

Print every factors of input number

func printDivisor(of number: Int) {
    for i in 1...number {
        if number % i == 0 {
            print(i, terminator: " ")
        }
    }
    print()
}

printDivisor(of: 10)
// 1 2 5 10

printDivisor(of: 100)
// 1 2 4 5 10 20 25 50 100

Print every common multiple of three and five below one hundred

func printCommonMultipleOfThreeAndFive() {
    for i in 1...100 {
        if (i % 3 == 0) && (i % 5 == 0) {
            print(i, terminator: " ")
        }
    }
    print()
}

printCommonMultipleOfThreeAndFive()
// 15 30 45 60 75 90

Determine the number that is prime number or not

func isPrime(number: Int) -> Bool {
    for i in 2..<number {
        if number % i == 0 {
            return false
        }
    }
    return true
}

isPrime(number: 7919)
// true

isPrime(number: 34573245731123)
// false

Gets a natural number and returns the number in the order of the number in the Fibonacci sequence

func getFibonacciNumber(of number: Int) -> Int {
    var fibonacciNumbers = Array(repeating: 0, count: number)
    
    fibonacciNumbers.insert(0, at: 0)
    fibonacciNumbers.insert(1, at: 1)
    
    for i in 2..<fibonacciNumbers.count {
        fibonacciNumbers[i] = fibonacciNumbers[i - 2] + fibonacciNumbers[i - 1]
    }
    return fibonacciNumbers[number - 1]
}

getFibonacciNumber(of: 4)
// 2

getFibonacciNumber(of: 30)
// 514229

Determine the year that is leap year or not

func isLeapYear(_ year: Int) -> Bool {
    if year % 4 == 0 {
        if year % 100 == 0 {
            if year % 400 == 0 {
                return true
            }
            return false
        }
        return true
    }
    return false
}

isLeapYear(200)
// false

isLeapYear(2016)
// true

Start a Github Blog with Hexo

Posted on 2019-11-11 Edited on 2019-12-03

How to creat a blog with hexo

$ brew install node
$ npm -v
$ sudo npm install -g hexo-cli
$ hexo
$ hexo init ghblog
$ cd ghblog
$ npm install
$ hexo new post {post-name}

Present View Example

ViewController

NextViewController

Class

Make this picture to a class with inheritance

Class

Make some classes related about real life

Make Caculator with class

Make some formulas with class

Closure

Optimize clousre

Optional, Enum

Combine Optional Strings and return a non Optional String

Calculate using enumeration

Convert celcius to fahrenheit and kelvin using enumertaion

Calculate using enumeration and recursive call

Collection Types (Array, Dictionary, Set)

Return the array of people that has “E” in their favorite fruits

Sort the array odd numbers go to forward and even numbers go to Backward

Print how many digit numbers are in array

Reverse a number

Determine the number has unique digits or not

Determine the array has unique letters or not

Organize a carnivores phylogeny

Get two natural number and combine them into one number

Compare two strings are the same or not

Print every factors of input number

Print every common multiple of three and five below one hundred

Determine the number that is prime number or not

Gets a natural number and returns the number in the order of the number in the Fibonacci sequence

Determine the year that is leap year or not

How to creat a blog with hexo