Swift 命名规则

Swift可以使用几乎任何字符作为常量和变量名，包括Unicode，但是不能包含数字符号、箭头、无效的Unicode、横线-、制表符、且不能以数字开头。

var π = 3.14

var 新空气软件 = "开发软件"

let 你好 = "你好世界"

整形的表现形式

二进制：前缀0b

八进制：前缀0o

十六进制：前缀0x

let decimalInteger = 14

let binaryInteger = 0b10001

let octalInterger = 0o21

let hexadecimlInteger = 0x11

let minValue = UInt8.min

let maxValue = UInt8.max

UInt8 是一个结构体struct

{

public struct UInt8 : UnsignedIntegerType, Comparable, Equatable {

public var value: Builtin.Int8

/// A type that can represent the number of steps between pairs of

/// values.

public typealias Distance = Int

/// Create an instance initialized to zero.

public init()

/// Create an instance initialized to `value`.

public init(_ value: UInt8)

public init(_builtinIntegerLiteral value: Builtin.Int2048)

/// Create an instance initialized to `value`.

public init(integerLiteral value: UInt8)

public static var max: UInt8 { get }

public static var min: UInt8 { get }

}

//类型别名

typealias NSInteger = Int

var value: NSInteger = 45

value = 12

print(value)

// 布尔类型

var tigerIsAnimal: Bool = true