AppleCEO

let numbers = [10, 83, 95, 100, 92]

// numbers의 요소 중 짝수를 걸러내어 새로운 배열로 반환
let evenNumbers: [Int] = numbers.filter { (number: Int) -> Bool in
    return number % 2 == 0
}
print(evenNumbers)
// [10, 100, 92]

AppleCEO

let someNumbers = [10, 8, 7, 1, 9]

// 초깃값이 0이고 someNumbers 내부의 모든 값을 더합니다.
let sum: Int = someNumbers.reduce(0, { (first: Int, second: Int) -> Int in
    //print("\(first) + \(second)") //어떻게 동작하는지 확인해보세요
    return first + second
})
// 35

// 초깃값이 5이고 someNumbers 내부의 모든 값을 뺍니다.

AppleCEO

struct TV {
    var channel: Int = 1
}

var tv = TV()

AppleCEO

struct TV {
    var channel: Int = 1
}

var tv = TV(channel: 15)

AppleCEO

struct TV {
    var channel: Int = 1
    
    init(channel: Int) {
        self.channel = channel
    }
}

var tv = TV(channel: 15)

AppleCEO

struct TV {
    var channel: Int = 1
    var brand: String
    
    init(channel: Int) {
        self.channel = channel
        self.brand = "LG"
    }
}

AppleCEO

struct Animal {
    let species: String
    init?(species: String) {
        if species.isEmpty { return nil }
        self.species = species
    }
}

var animal = Animal(species: "")

AppleCEO

struct TV {
    var channel: Int = 1
    var brand: String
    
    init(channel: Int) {
        self.channel = channel
        self.brand = "LG"
    }
    
    init() {

AppleCEO

class Radio {
    var channel: Double
    
    init(channel: Double) {
        self.channel = channel
    }
}

let radio = Radio(channel: 89.1)

AppleCEO

class Radio {
    var channel: Double
    
    init(channel: Double) {
        self.channel = channel
    }
    convenience init(){
        self.init(channel: 103.5)
    }
}