swift-学习之路,字典、数组、循环-控制流
发布时间:2020-12-14 01:54:44 所属栏目:百科 来源:网络整理
导读://// ViewController.swift// UIWindowimport UIKitimport Foundationclass ViewController: UIViewController { @IBOutlet weak var usrNameLabel: UITextField! @IBOutlet weak var passwdLabel: UITextField! @IBAction func btnTouch(sender: AnyObject)
// // ViewController.swift // UIWindow import UIKit import Foundation class ViewController: UIViewController { @IBOutlet weak var usrNameLabel: UITextField! @IBOutlet weak var passwdLabel: UITextField! @IBAction func btnTouch(sender: AnyObject) { println("usrName is (self.usrNameLabel.text)"); println("passwdLabel is (self.passwdLabel.text)"); } override func viewDidLoad() { super.viewDidLoad() println("Hello World"); let label = "The width is" let width = 90 let widthLabel = label + String(width) println("widthLabel is (widthLabel)") var shoppingList = ["catfish","water","tulips","blue paint"] shoppingList[1] = "bottle of water" var occupations = [ "Malcolm":"Captain","Kaylee":"Machanic",] occupations["Jayne"] = "Public Relation" //初始化一个空的数组 let emptyArray = [String]() //初始化一个空的字典 let emptyDictionary = [String : Float]() let individualScores = [75,43,103,87,12] var teamScore = 0 //循环语句的使用 for score in individualScores{ if(score > 50) { teamScore += 3 } else { teamScore += 1 } } print(teamScore) var optionalString:String? = "Hello" optionalString == nil var optionalName:String? = "John Appleasee" var greeting = "Hello" /*if let name = optionalName{ greeting = "Hello,(name)" } */ //如果可选值为nil 则不会执行代码块的内容 /* optionalName = nil if let name = optionalName{ greeting = "Hello (name)" } print(greeting) */ optionalName = nil if let name = optionalName{ greeting = "Hello (name)" }else{ greeting = "-执行的第二句代码-" } print(greeting) /** switch 支持任意类型的数据以及各种比较操作-不限于整数和表达式 // 不需要加break */ let vegetable = "red pepper" switch vegetable{ case "celery": let vegetableComment = "Add some raisins and make ants on a log." case "cucumber","watercress": let vegetableComment = "That would make a good tea sandwich." case let x where x.hasSuffix("pepper"): let vegetableComment = "Is it a spicy(x)?" default: let vegetableComment = "Everything tastes good in soup." } /// 这里用于比较字典中的最大值并且把变量是哪种类型的输出来 let interestingNumbers = [ "Prime":[2,3,5,7,11,13],"Fibonacci":[1,1,2,8],"Square":[1,4,9,16,25],] var largest = 0 var name:String? for (kind,numbers) in interestingNumbers{ for number in numbers{ if number > largest{ largest = number name = kind } } } println(largest) println(name) /** 1+2+....+100; */ //这里用起来十分的方便,程序不运行会有提示,可以试试如果i的值不++ 可以观察一下 var sum = 0 var i = 0 while i <= 100{ sum += i i++ } print(sum) /** ..< 和 ... 表示范围 ..< 不包含上届 ...包含上届 */ var firstForLoop = 0 for i in 0..<3{ firstForLoop += i } print(firstForLoop) var secondForLoop = 0 for var i = 0;i < 3; ++i{ secondForLoop += i; } print(secondForLoop) //self.usrNameLabel. // Do any additional setup after loading the view,typically from a nib. } override func didReceiveMemoryWarning() { super.didReceiveMemoryWarning() // Dispose of any resources that can be recreated. } } (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |
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