1.常量:使用let聲明
let str = "kuangjunjie"
2.變量:使用var聲明
var str = "kuangjunjie"
3.整型
有符號整形：Int，Int8，Int16恢准，Int32句各，Int64
無符號整形：UInt，UInt8巧鸭，UInt16瓶您，UInt32，UInt64
4.浮點型
Float：32位浮點數(shù)類型
Double：64位浮點數(shù)類型
5.布爾型：Bool
let bool1 = true
let bool2 = false
6.字符串
// (1)判斷是否為空:isEmpty
let str = ""
if str.isEmpty {
print("空字符串")
}
// (2)獲取字符數(shù)量: str.characters.count
let str = "kuangjunjie"
print("\(str.characters.count)個字符")
// (3)檢查字符是否有特定的前綴/后綴:
let str = "kuangjunjie"
if str.hasPrefix("kuang") {
print("str字符串有kuang前綴")
}
if str.hasSuffix("jie") {
print("str字符串有jie后綴")
}
//（4）還可以用“\()”在字符串里包裹變量纲仍，常量
let age = "18"
let say = "我永遠(yuǎn)\(age)歲"
// (5）大小寫轉(zhuǎn)換：通過字符串的uppercaseString呀袱、lowercaseString屬性來訪問一個字符串的大寫/小寫
let str = "name: Kuangjunjie"
var uppercasedStr = str.uppercased()//NAME: KUANGJUNJIE
var lowercasedStr = str.lowercased()//name: kuangjunjie
7.字符: Character
var character : Character = "@"
8.元組: ( , )
let tuple = (frist: "1",second:"2")
print(tuple.frist) // 1
