//object & class class Shape{ var numberOfSides:Int = 0 var name: String init(name: String){ self.name = name } func simpleDescription() -> String{ return "A shape with \(numberOfSides) sides" } } var shape = Shape(name: "kay") shape.numberOfSides = 7 var shapeDescription = shape.simpleDescription() //하위클래스:상위클래스 class Square: Shape{ var sideLength: Double init(sideLength: Double, name: String){..

import UIKit //function func greet(person: String, day: String) -> String{ return "hello \(person)" } greet(person: "ddd", day: "wed") //여러개의 return 값을 줄 수 있다. func calculateStatistics(scores: [Int])->(min: Int, max:Int, sum:Int){ var min = scores[0] var max = scores[0] var sum = 0 for score in scores { if score>max{ max = score }else if scoreInt{ var y = 10 func add(){ y += 5 } add() return y }..

*if else var optionalString: String? = nil print(optionalString == nil) //true var greeting = "Hello" if let name = optionalString{ greeting = "Hello, \(name)" }else{ greeting = "Hello, stranger" } print(greeting); //Hello, stranger var optionalString2: String? = "jason" print(optionalString2 == nil) //false //print(optionalString2) //만약 optional변수를 그냥 print할경우 -> let변수 사용해야함 //경고발생 expession im..

변수: var 상수: let var str = "Hello, playgroundff" str = "Hello, playgroundffffff" print(str) var implicitInteger = 80 //타입을 지정하지 않으면 처음 넣는 값이 타입으로 정해짐 let implicitDouble = 70.0 let explicitDouble:Double = 70 var k:String //k="test" //error띄어쓰기까지 check k = "test" //k = 0 //error 이미 string타입으로 정해졌기때문에 int형의 값을 넣을 수 없음 var kk : Int //kk = 9.0 //error 자동 형변환 없음 kk = 9 var j : Double j = 9.1 j = 10 //*..