swift简单的赋值
//: Playground - noun: a place where people can play import UIKit var str = "Hello,playground" var myVar = 45 myVar = 90 let myCon = 90 let implictInteger = 70 let implicitDouble = 80.0 let explicitDouble: Double = 700 let expFloat: Float = 4 //值永远不会隐式转换为另一种类型。如果你需要把一个值转换到不同类型,需要明确的构造一个所需类型的实例。 let label = "The width is " let width = 100 let widthLabel = label + String(width) //实现字符串中包含值:以小括号来写值,并用反斜线()放在小括号之前 let apples = 3 let oranges = 5 let appleSummary = "I have (apples) apples." let fruitSummary = "I have (apples + oranges) pieces" let impdouble = 90.0 let tom = "name" let labe = "go to (impdouble) (tom) fname" //创建一个数组和字典使用方括号"[]",访问其元素则是通过方括号中得索引或键。 var shoppingList = ["catish","water","tulips","blue paint"] shoppingList[1] = "bottle of water" var occupations = [ "Malcolm": "Captain", "Kaylee": "Mechanic", ] occupations["Jayne"] = "Public Re" //创建一个空得数组或字典,使用初始化语法: let emptyArray = [String]() let emptyDictionary = Dictionary<String,Float>() //如果类型信息无法推断,你可以写空的数组"[]" 和空的字典"[:]",例如你设置一个知道变量并传入参数到函数: shoppingList = [] occupations = [:] //数字字面量(Literals) var decimalInteger = 17//十进制 var binarryInteger = 0b10001//二进制 let octalInteger = 0o21//八进制 let hexadecimalInteger = 0x11//十六进制 //可选值绑定 var temp1: String? = "123" if let temp2 = temp1?.toInt() { println("(temp1) has an (temp2)") } (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! |