一、常量 & 变量
//常量let constantsTeam =1//变量var variablesTeam =2
尽可能使用常量，这样更清晰并且内存更不容易肾亏。
二、显示/隐式指定类型
//隐式let inferredTeam =3//显式let explicitTeam:Int =4
三、字符串输出
//通过\(变量或常量名)来引用组合字符串PRintln("\(inferredTeam) is bigger than \(variablesTeam)!")
四、类和方法
//类使用class关键字声明classTipCalculator {//在类中创建属性let total: Double
let taxPct: Double
let subtotal: Double//属性必须在声明时赋予一个初始值，或者在initializer里，否则必须声明其为optional（这里使用的是initializer）init(total:Double, taxPct:Double) {
self.total=total
self.taxPct=taxPct
subtotal= total / (taxPct +1)
}//方法使用func关键字声明，返回Double类型func calcTipWithTipPct(tipPct:Double) ->Double {returnsubtotal *tipPct
}//无返回值方法func printPossibleTips() {
println("15%: \(calcTipWithTipPct(0.15))")
println("18%: \(calcTipWithTipPct(0.18))")
println("20%: \(calcTipWithTipPct(0.20))")
}
}//创建类实例对象，通过类实例对象调用类中的方法let tipCalc = TipCalculator(total:33.25, taxPct:0.06)
tipCalc.printPossibleTips()
五、数组和循环
//1let possibleTipsInferred = [0.15,0.18,0.20]
let possibleTipsExplicit:[Double]= [0.15,0.18,0.20]//2forpossibleTipinpossibleTipsInferred {
println("\(possibleTip*100)%: \(calcTipWithTipPct(possibleTip))")
}//3foriin0..<possibleTipsInferred.count {
let possibleTip=possibleTipsInferred[i]
println("\(possibleTip*100)%: \(calcTipWithTipPct(possibleTip))")
}
六、字典Dictionary
//1func returnPossibleTips() ->[Int: Double] {
let possibleTipsInferred= [0.15,0.18,0.20]
let possibleTipsExplicit:[Double]= [0.15,0.18,0.20]//创建一个空字典var retval = Dictionary<Int, Double>()forpossibleTipinpossibleTipsInferred {
let intPct= Int(possibleTip*100)//赋值给字典retval[intPct] =calcTipWithTipPct(possibleTip)
}returnretval
}
七