1.swift进制认识:
let a = 17 //十进制17
let b = 0b10001 // 二进制0b前缀
let c = 0o721 //八进制0o前缀
let d = 0xF101 //十六进制0x前缀
print(a,b,c,d) //显示结果
2.数据类型转换
var bookPrice : Int8 = 79,itemPrice : Int16 = 48
//类型强转-低转高
var int8toint16 : Int16 = Int16(bookPrice)
print(int8toint16)
print(Int16(bookPrice))
//类型强转-高转低
var int16toint8:Int8 = Int8(itemPrice)
print(int16toint8)
var a = itemPrice+Int16( bookPrice)
print(a,Int16.max)
print(bookPrice+Int8(itemPrice))
//同一数据类型相加
var all = Int16(bookPrice) + itemPrice
print("all:\(all)")
3.变量赋值
var str = "Swift"
var pi:Double = 3.14
var visited:Bool = true
var str2:String = str
var a:Int
var b = a = 20
va