swift：基本数据类型

//: Playground - noun: a place where people can play

import UIKit

//整数类型

let int_a =10

let int_b :Int

let int_c :Int
= 10

//注意不能 let int_c (即是在定义常量或者变量时，在隐示声明的时候必须初始化)

//字符串

let string_a ="i like eat"

let string_b:String

let string_c:String
= "i like eat"

//类型强制转换

let apple ="the number of apple is "

let number =10

let number_apple=apple
+ String(number)

print("the number is\(number)")

//
浮点数

let float_a =1.0

let float_b:Float

let float_c:Float=1.0

let double_a =1.99

let double_b:Double

let double_c:Double=1.99

//布尔类型

let bool_a=true

let bool_b=false

let bool_c:Bool

let bool_d:Bool=true

//数组与字典

let emptyArray = [String]()

var array1 = ["aa","bb",12]

let emptyDictionary =Dictionary<String,Float>()

var dictionary1 = ["xiaoming":10,"xiaohong":12]

dictionary1["xiaofei"]
= 12//添加元素
print(dictionary1)

//枚举
enum Person{

case
小明

case
小红

case
小花
}
let person1:Person = .小明
let person2:Person = .小红
let person3:Person = .小花

let person:Person =
person2

switch person{

case .小明:

print("是小明")

case .小红:

print("是小红")

case .小花:

print("是小花")
}