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")

}