swift的一些常见用法

//1.输出

print("Hello,PlayGround")

//2.常量和变量

var a="我是变量"

let b="我是常量"

//3.指明类型
let letInteger :int_fast32_t =
70
let letDouble :
Double = 70.0
let letString :
NSString = "HelloSwift"

//4.转换字符串：String()或\()
let myString =
"myInt is"
let myInt =
94
let myString2 =
myString + String(myInt)
let myString3 =
"myInt is  \(myInt)"

//5.数组创建与调用

var array = ["one" ,
"two","three","four"]
var getTwo=array[1]

//6.数组字典创建与调用

var dictionary = ["oneName":"I am one value","twoName":"I am two value","threeName":"I
am three value"]
var getTwoValue =
dictionary["twoName"]

//7.for语句
for item
in array{
   
var i = item
}

//8.函数
func getUseName(loginName :String)->String
{

    return
"Lily"
}

//9.枚举
enum Week{
   
case
星期一
   
case
星期二
   
case
星期三
   
case
星期四
   
case
星期五
   
case
星期六
   
case
星期天
}

//10.Switch语句
var today =
"星期一"

switch today
{
   
case "星期一":
       
print("今天是星期一")
   
case "星期二":
       
print("今天是星期二")

    default:
       
print("今天是星期几")
}

//11.类
class Person :
NSObject
{
   
var userName : String
   
var userAge = 0

    override
init() {
       
userName="loij"
    }
}