數(shù)據(jù)基本類型

變量：使用var聲明

var str:String = "GlenRiver"

常量：使用let聲明

let count:Int = 5

整型

• 有符號整形：Int，Int8，Int16，Int32，Int64
• 無符號整形：UInt，UInt8，UInt16，UInt32，UInt64

浮點(diǎn)型

• Float：32位浮點(diǎn)數(shù)類型
• Double：64位浮點(diǎn)數(shù)類型

布爾型

• Bool

字符串

• String

判斷是否為空 -- isEmpty

var str: String = ""
if str.isEmpty{
    print("I'm a null string")
}

獲取字符數(shù)量 -- string.characters.count

let str = "GlenRiver"
print("\(str) has \(str.characters.count) characters")

檢查字符串是否有特定前綴/后綴 -- hasPrefix/hasSuffix

var str = "Chan.GlenRiver.exe"
if str.hasSuffix(".exe"){
    print("\(str) has postfix '.exe'")
}
if str.hasPrefix("Chan."){
    print("\(str) has prefix 'Chan.'")
}

還可以用“\()”在字符串里包裹變量，常量

let myName = "GlenRiver"
print("Welcome to \(myName) homepage")

大小寫轉(zhuǎn)換 -- uppercase()、lowercase()、capitalized

let str = "Welcome to GlenRiver.com"

//swift3.0的用法
//WELCOME TO GLENRIVER.COM
var upperStr = str.uppercased()
//welcome to glenriver.com
var lowerStr = str.lowercased()
//Welcome To Glenriver.Com
var capitalizedStr = str.capitalized

//swift2.2的用法
//var upperStr = str.uppercaseString
//var lowerStr = str.lowercasedString
//var capitalizedStr = str.capitalizedString

字符

• Character

var doller:Character = "$"

元組

let myParam = (first:"game",second:1234)
print("The first element of tuple is \(myParam.first)")
print("The second element of tuple is \(myParam.second)")

轉(zhuǎn)載，請表明出處！ GlenRiver

代碼下載：GR-Swift.rar

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