swift基本知识点的源码_app

概述基础的练习代码如下： // print("hello world");// let explictFloat : Float = 4;// print(explictFloat)// let label = "My age is ";// let age = 18;// let labelAge = label + String(age);// print(labelAge);
基础的练习代码如下：
// print("hello world");// let explictfloat : float = 4;// print(explictfloat)// let label = "My age is ";// let age = 18;// let labelAge = label + String(age);// print(labelAge);// let apples = 3;// let oranges = 5;// let appleSummary = "I have \(apples) apples\n";// print(appleSummary);// let fruitSummary = "I have \(apples + oranges) pIEces of fruit";// print(fruitSummary);// let abc = 38.8;// let label = "My number is \(abc)";// print(label);// var shopPingList = ["apple","orange","banana","milk"]; //数组// print(shopPingList[1]);// var peopleSex = ["Jack" : "I'm a boy","lisa" : "I'm a girl"]; //字典// print(peopleSex["Jack"]);// let indivIDualscores = [75,43,103,87,12]; //if else 进行判断// var teamscore = 0;// for score in indivIDualscores {// // if score > 50 {// teamscore += 3;// } else {// teamscore += 1;// }// // }// // print(teamscore);// var optionalname: String? = "Jack"; //用问号来标记某个变量的值是可选的// optionalname = nil;// var greeting = "Hello!";// if let name = optionalname {// greeting = greeting + String(name);// print(greeting);// // }else{// greeting = greeting + String(optionalname);//+ "lisa";// print(greeting);// }// let @R_404_5457@ble = "red pepper"; //switch 的使用// // switch @R_404_5457@ble {// case "celery":// let @R_404_5457@bleComment = "Hi I'm will go home";// print(@R_404_5457@bleComment);// case "cucumber","watercress":// let @R_404_5457@bleComment = "I'm lisa,come here";// print(@R_404_5457@bleComment);// case let x where x.hasSuffix("pepper"):// let @R_404_5457@bleComment = "Is it a spicy \(x)?";// print(@R_404_5457@bleComment);// default:// let @R_404_5457@bleComment = "EveryThing is taste good in a soup";// print(@R_404_5457@bleComment);// }// // let interestingNumbers = [ //for-in 实现字典的遍历// "Prime" : [2,3,5,7,11,13],// "Fibonacci" : [1,1,2,8],// "Square" : [1,4,9,16,25],// ]// // var largest = 0;// // for (kind,numbers) in interestingNumbers {// // for number in numbers {// if number > largest {// largest = number;// }// }// print(largest);//// print(kind,largest);// }// // var n = 2; //while实现循环// while n < 100 {// n = n*2;// }// // print(n);// // var m = 2; //repeat-while 实现循环// // repeat {// m = m*2;// }while m < 100// // print(m);// //使用 for 循环// var firstForLoop = 0;// // for var i = 0;i < 3;++i {// // firstForLoop += i;// }// // print(firstForLoop);// //函数和闭包// func greet(name: String,day: String) ->String{// // return "Hello \(name),Today is \(day).";// }// // print(greet("Jack",day: "Tuesday"));// func getGasPrice() ->(Double,Double,Double){ //使用一个元组来返回多个值。// // return (3.59,3.69,3.79);// }// // // print(getGasPrice());// //函数的参数是可变的，用一个数组来获取它们// // func sumOf(numbers: Int...) ->Int{// // var sum = 0;// for number in numbers {// // sum += number;// }// print(sum);// return sum;// }// //// sumOf();// sumOf(42,597,12);        class nameShape {            var numberOfsIDes: Int = 0;            var name: String;            init(name: String){                self.name = name;            }            func simpleDescription() ->String{            return "A shape with \(numberOfsIDes) sIDes.";            }        }        class Square:nameShape{            var sIDeLength: Double;            init(sIDeLength: Double,name: String){                self.sIDeLength = sIDeLength;                super.init(name: name);                numberOfsIDes = 4;            }            func area() ->Double {                return sIDeLength * sIDeLength;            }            overrIDe func simpleDescription() -> String {                return "A square with sIDes of length \(sIDeLength)";            }        }// let test = Square(sIDeLength: 5.5,name: "lili");// // let area = test.area();// print(area);// // let description = test.simpleDescription();// print(description);// class Circle:nameShape { //圆的类定义// var radius: Double;// init(radius: Double,name: String){// self.radius = radius;// super.init(name: name);// }// // func area() ->Double{// // return M_PI * radius * radius;// // }// // overrIDe func simpleDescription() -> String {// // return "A Cicle with radius of \(radius)";// }// }// // let test = Circle(radius: 4.8,name: "myCircle");// // print(test.name);// // let area = test.area();// print(area);// // let description = test.simpleDescription();// print(description);// //         class EquilateralTriangle: nameShape{            var sIDeLength: Double = 0.0;            init(sIDeLength: Double,name: String){                self.sIDeLength = sIDeLength;                super.init(name: name);                numberOfsIDes = 3;            }            func area() -> Double {                return sIDeLength * sIDeLength;            }            var perimeter: Double{     //属性可以有 getter 和 setter 。                get {                    return 3.0 * sIDeLength;                }                set {                    sIDeLength = newValue/3.0;    //在 perimeter 的 setter 中,新值的名字是 newValue。你可以在 set 之后显示的设置一个名 字。                }            }            overrIDe func simpleDescription() -> String {                return "An equilateral triangle with sIDes of length \(sIDeLength)";            }        }// let triangle = EquilateralTriangle(sIDeLength: 5,name: "my Triangle");// // print(triangle.perimeter);// // triangle.perimeter = 9.9;// // print(triangle.sIDeLength);// // let description = triangle.simpleDescription();// // print(description);        //如果你不需要计算属性但是需要在设置一个新值之前运行一些代码,使用willSet和dIDSet。 比如,下面的类确保三角形的边长总是和正方形的边长相同。        class TriangleAndSquare {            var triangle: EquilateralTriangle {                willSet {                    square.sIDeLength = newValue.sIDeLength;                }            }            var square: Square {                willSet {                    triangle.sIDeLength = newValue.sIDeLength;                }            }            init(size: Double,name: String){                square = Square(sIDeLength: size,name: name);                triangle = EquilateralTriangle(sIDeLength: size,name: name);            }        }        let triangleAndSquare = TriangleAndSquare(size: 10,name: "another test shape");        print(triangleAndSquare.square.sIDeLength);        print(triangleAndSquare.triangle.sIDeLength);        triangleAndSquare.square = Square(sIDeLength: 50,name: "larger Square");        print(triangleAndSquare.triangle.sIDeLength);