String , Hexa Decimal ===> Color 로 변환

static func rgb(_ red: CGFloat, _ green: CGFloat, _ blue: CGFloat, _ alpha: CGFloat = 1.0) -> UIColor {

        return UIColor(red: red / 255.0, green: green / 255.0, blue: blue / 255.0, alpha: alpha)

    }

static func hexadecimal(_ value: UInt32, _ alpha: CGFloat = 1.0) -> UIColor {

        return UIColor.rgb(CGFloat((value & 0xFF0000) >> 16),

                           CGFloat((value & 0xFF00) >> 8),

                           CGFloat(value & 0xFF),

                           alpha)

    }

static func hexadecimal(_ value: String, _ alpha: CGFloat = 1.0) -> UIColor {

        let alphanumerics = value.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)

        return UIColor.hexadecimal(UInt32(alphanumerics, radix: 16) ?? 0, alpha)

    }

String에서 numeric 또는 alphanumerics 추출

1. String에서 numeric 또는 alphanumerics  추출 예제

let value = "39_ABCD*^%()!@ \n~_384749.374"

let alphanumerics = value.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)

let numeric = value.components(separatedBy: CharacterSet.decimalDigits.inverted).joined()

출력 : 

alphanumerics : 39_ABCD*^%()!@ 

~_384749.374

numeric : 39384749374

숫자를 통화로 표기

1. 숫자를 통화로 변환 기본

let value = 39384749.374

let decimalFormatter = NumberFormatter()

decimalFormatter.numberStyle = NumberFormatter.Style.decimal

let currency = decimalFormatter.string(from: value as NSNumber) ?? String(value)

출력 => "39,384,749.374"

2. 세퍼레이터 변경

let value = 39384749.374

let decimalFormatter = NumberFormatter()

decimalFormatter.numberStyle = NumberFormatter.Style.decimal

decimalFormatter.groupingSeparator = "#"

let currency = decimalFormatter.string(from: value as NSNumber) ?? String(value)

출력 => "39#384#749.374"

2. 통화기호 표시

let value = 39384749.374

let decimalFormatter = NumberFormatter()

decimalFormatter.numberStyle = NumberFormatter.Style.currency

decimalFormatter.currencySymbol = "￦"

let currency = decimalFormatter.string(from: value as NSNumber) ?? String(value)

출력 => "￦39,384,749.37"

범위연산 (range operators) 활용

1. 기본




2. 배열

let numbers = [10, 20, 30, 40, 50]

let part1 = numbers[0 ..< 5]

let part2 = numbers[2...]

let part3 = numbers[..<4]

let part4 = numbers[0...3]

print("part1 = \(part1)")

print("part2 = \(part2)")

print("part3 = \(part3)")

print("part4 = \(part4)")

part1 = [10, 20, 30, 40, 50]

part2 = [30, 40, 50]

part3 = [10, 20, 30, 40]

part4 = [10, 20, 30, 40]

3. Int Array 만들기

1)

let day = [Int](1...31)

print("15 is ", day.contains(15))

print("40 is ", day.contains(40))

print(day)

15 is  true

40 is  false

[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31]

2)

let lessThanFive = 0.0..<5.0

print(lessThanFive.contains(3.14))  // Prints "true"

print(lessThanFive.contains(5.0))   // Prints "false"

4. 스트링

let text = "Hello World!"

if let firstSpace = text.index(of: " ") {

    print(text[text.startIndex..<text.endIndex])

    

    print("-----------")

    print(text[text.startIndex...])

    print(text[..<firstSpace])

    

    print("-----------")

    print(text[text.startIndex...firstSpace])

    

    let nextIndex = text.index(firstSpace, offsetBy: 1)

    print(text[text.startIndex...nextIndex])

}

Hello World!

-----------

Hello World!

Hello

-----------

Hello 

Hello W

Self vs self vs Type

1. Type vs self

메타타입은 타입의 타입을 의미한다.

 

class SomeClass {

}

/*

SomeClass.Type 은 타입의 타입을 정의

SomeClass.self 은 타입의 타입값

*/

let someInstance: SomeClass.Type = SomeClass.self

/*

인스턴스메써드에서 self 는 인스턴스 자기자신을 자리킴

*/

class SomeClass {

   var member = "Hello"

   func someFunction {

         self.member = "World"

   }

}

/*

타입메써드에서 self 는 타입을 자리킴

*/

class SomeClass {

  static var staticMember = "Hello"

   static func someFunction {

         self.staticMember = "World"

   }

}

2. Self

Self는 자기자신의 Type을 가리킴,  상속받은것 까지 포함.

//사용예1

 extension SomeClass where Self: OtherClass {

}

//사용예2

func someFunction() -> Self {

}

//사용예3

let vc = someInstance as? Self

let allValues: [Self] = ~

let value: Self = ~

 

Generic Type 에서 Factory 함수 정의 하는 방법

리턴타입에 타입매개변수를 정의해도되고, 생략해도 된다.

class TempleteClass<T> {

    var value: T

    

    init(param: T) {

        self.value = param

    }

    

    static func create1(param: T) -> TempleteClass<T> {

        let request = TempleteClass(param: param)

        return request

    }

    

    static func create2(param: T) -> TempleteClass {

        let request = TempleteClass(param: param)

        return request

    }

}

extension TempleteClass {

    static func create3(param: T) -> TempleteClass<T> {

        let request = TempleteClass(param: param)

        return request

    }

    

    static func create4(param: T) -> TempleteClass {

        let request = TempleteClass(param: param)

        return request

    }

}