Swift入门第二天

最近的天气真的很奇怪，但是还是需要继续在Swift上下功夫，接下来我来介绍下swift中相关知识点，如：元组，数组，字典，结构，枚举类型，函数定义，逻辑判断，for循环。这些语法在其他热门语言中也是必备的知识点，接下来给一段代码，相信大家运行后一定会有所掌握。

上次忘了告诉大家如何创建可运行的Swift程序，接下来我用图示的方式说明下：

第一步：打开Xcode，选择Project，进入如下界面：

点击Next,选择Swift语言，并填写完整项目名。next后，选择程序存放位置就搞定了.基本语法学习通过创建这个工程就可以了

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

import UIKit

var str = "Hello, playground"

//1.元组

var 元组 = (120,"test");  //可以关联不同的类型

元组.0

元组.1

//tuple

let httpStatus = (statusCode:404,statusDesc:"Not Found");

httpStatus.statusCode;
httpStatus.statusDesc;
httpStatus.0
httpStatus.1

//2.数组

var shoppingList = ["string",120,35.5,true];
shoppingList[0];
shoppingList[1];
shoppingList[2];

if (shoppingList.isEmpty)
{
    print("数组为空");
}
else
{
    print("数组非空");
}

shoppingList.count

shoppingList.append("水费");
shoppingList.append("电费");
shoppingList.append("网费");

shoppingList += ["hello","world","tom"];

shoppingList

var firstItem = shoppingList[1];

shoppingList[1...5] = ["西瓜","南瓜","冬瓜"];

shoppingList

var someInts = [Int32]();  //数组的初始化
someInts.append(1);
someInts
//someInts.append("test");   //类型不一致
someInts

//3.字典

var games:[String:String] = ["暗黑":"1级","仙剑":"2级","CS":"3级"];
games
games["CS"]

let keyValue = ["k1":"v1","k2":"v2","k3":"v3"];

keyValue["k2"];

//字典的遍历
for item in keyValue.values
{
    print("项次依次是:\(item)");
}

//初始化一个字典

var numberValue = [Int32:String]();

numberValue[16] = "sixteen";

numberValue

//结构，swift的区别：结构体里面可以定义方法
struct Sword
{
    var length : Float;
    let name:String;
    func description()
    {
        print("这是一个名字为\(name)的武器，长度\(length)");
    }
}

var sword:Sword = Sword(length: 1.2, name: "巨阙");

//枚举类型
enum FlatForm
{
    case Windows
    case Mac
    case Linux
}

var OS:FlatForm = FlatForm.Windows;

//函数定义

func sayHello(personName:String)->String
{
    return "hello welcome";
}

func say()->Int32
{
    return 0;
}

sayHello("kitty");
say();

func sayHelloLabel(personNameLabel personName:String)->String
{
    return "hello world";
}

sayHelloLabel(personNameLabel: "tom");


var a = 10;
var b = 20;

var addResult = a + b;
var subResult = a - b;
var mutResult = a * b;
var divResult = a / b;
var remainResult = a % b;

var sum = 0;
sum += a;

//逻辑判断
1==1
1>2

//三目运算符 ?:
var flag = true;
var viewHeight = 480 + (flag ?88:0);

//for 循环
var sum2 = 0;
for i in 1...10
{
    //i++;
    sum += i;
}