Swift基础

//
//  ViewController.swift
//  Swift基础运算符
//
//  Created by mibo02 on 16/12/21.
//  Copyright © 2016年 mibo02. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

   override func viewDidLoad() {
       super.viewDidLoad()
       //var 是变量 let 指常量
       //1.赋值运算符
       //2.数值运算
       let str = "hello," + "world"
       print(str)
       
       let contentHeight = 40
       let hasHeader = true
       var rowHeight = contentHeight
       if hasHeader {
           rowHeight = rowHeight + 50
       } else {
           rowHeight = rowHeight + 20
       }
       print(rowHeight)
       
       //区间运算符
       //1.闭区间运算符
       for index in 1...5 {
           //包含了1到5之间的所有数字
           print(index * 5)
       }
       
       //2.半闭区间
       let names = ["Anna","Alex","Brian","Fengfeng"];
       let count = names.count;
       for i in 0..<count {
           print("第\(i + 1)个人交 \(names[i])")
       }
       
       //逻辑与
       let first = true
       let second = false
       if first && second {
           print("成功了亲")
       } else {
           print("失败了亲")
       }
       //逻辑与
       let haseKey = false
       let hasValue = true
       if haseKey || hasValue {
           print("峰峰")
       } else {
           print("不好")
       }
       //组合逻辑
       //使用括号来明确优先级
       if (first && second) || haseKey || hasValue {
           print("你好，Man")
       } else {
           print("一点都不好对我")
       }
       /*
字符串字面量可以包含以下特殊字符：
转移特殊字符 \0 (空字符)、\\(反斜线)、\t (水平制表符)、\n (换行符)、\r (回车符)、\" (双引号)、\' (单引号)。
单字节 Unicode 标量，写成 \xnn，其中 nn 为两位十六进制数。
双字节 Unicode 标量，写成 \unnnn，其中 nnnn 为四位十六进制数。
四字节 Unicode 标量，写成 \Unnnnnnnn，其中 nnnnnnnn 为八位十六进制数。
       */
       //双引号
       let wiseWords = "\"我是要成为海贼王的男人\" - 路飞"
       print(wiseWords)
       //初始化空字符串
       var emptyString = ""
       var anotherEmptyString = String()//初始化String实例
       emptyString = "峰峰"
       anotherEmptyString = "小蓉"
       if emptyString.isEmpty {
           print("这是一个空字符串")
       } else {
           print("....")
       }
       
       //字符串的可变性
       var variableString = "Horse"
       variableString += " and carriage"
       print(variableString)
      
       let yenSign: Character = "¥"
       
       //字符串可以通过相加减进行拼接
       //字符串插入值
       let multiplier = 3
       let message = "\(multiplier) times 2.5 is \(Double(multiplier)*2.5)"
       print(message)
       
       
       //比较字符串
       let quotation = "We're a lot alike, you and I."
       let sameQuotation = "We're a lot alike, you and i"
       if quotation == sameQuotation {
           print("我们两个是一样的")
       } else {
           print("我们两个是不一样的")
       }
       //前缀、后缀相等
       let romeoAndJuliet = [
           "Act 1 Scene 1: Verona,A public place",
           "Act 1 Scene 2: Capulet's mansion",
           "Act 1 Scene 3: A room in Capulet's mansion",
           "Act 1 Scene 4: A street outside Capulet's mansion",
           "Act 1 Scene 5: The Great Hall in Capulet's mansion",
           "Act 2 Scene 1: Outside Capulet's mansion",
           "Act 2 Scene 2: Capulet's orchard",
           "Act 2 Scene 3: Outside Friar Lawrence's cell",
           "Act 2 Scene 4: A street in Verona",
           "Act 2 Scene 5: Capulet's mansion",
           "Act 2 Scene 6: Friar Lawrence's cell" ]
       var act1 = 0
       for scene in romeoAndJuliet {
           if scene.hasPrefix("Act") {
               act1 += 1
           }
       }
       print("There are \(act1) scenes in Act 1")
       
       
       //大写小写字符串
       let normal = "Could you help me, please?"
       let shouty = normal.uppercased() // shouty 值为 "COULD YOU HELP ME, PLEASE?"
       let whispered = normal.lowercased() // whispered 值为 "could you help me, please?"
       print(shouty)
       
       
       //数组
       var shopping = ["eggs","milk"]
       //判断数组是否为空
       if shopping.isEmpty {
           print("空")
       }else {
           print("非空")
       }
       //往数组末尾添加一个元素
       shopping.append("Flour")
       //或者
       shopping += ["Chocolate Spread", "Cheese", "Butter"]
       
       let removestring = shopping.removeFirst()
       print(removestring)
       
       
       //字典
       //var airports: Dictionary<String, String> = ["TYO": "Tokyo", "DUB": "Dublin"]
       
       var airports = ["TYO": "Tokyo", "DUB": "Dublin"]
       //往字典中添加元素
       airports["fengfeng"] = "好人"
       print(airports)
       //删除字典中的元素
       airports["TYO"] = nil;
       print(airports)
       let removedValue = airports.removeValue(forKey: "DUB")
       print(airports)
       //字典初始化
       var namesOFIntegers = Dictionary<Int, String>()
       print(namesOFIntegers)
       //或者
       namesOFIntegers[16] = "six"
       namesOFIntegers = [:]
       
       //函数调用
       print(sayhello(personName: "fengfengaima"))
       print(halfOpenRangeLength(start: 4, end: 10))
       print(sayHelloWorld())
       print(sayGoodbye(personName: ""))
       
   }
   
   //函数
    func sayhello(personName:String) -> String {
       return "Hello, \(personName)"
   }
   //多参数函数
   func halfOpenRangeLength(start: Int, end:Int) -> Int {
       return end  - start
   }
   
   //无参函数
   func sayHelloWorld() -> String {
       return "hello world"
   }
   //没有返回值的函数
   func sayGoodbye(personName:String) {
       print("这个函数没有返回值")
   }
   
   override func didReceiveMemoryWarning() {
       super.didReceiveMemoryWarning()
       // Dispose of any resources that can be recreated.
   }


}