swift—1

swift学习资料

http://www.360doc.com/content/14/0607/22/8772388_384675910.shtml

http://www.cocoachina.com/newbie/tutorial/
安装mac os x 10.10
http://jingyan.baidu.com/article/ab69b270de254f2ca7189fb7.html
http://jingyan.baidu.com/article/af9f5a2d20ba3343140a4592.html


创建switf ox项目（略）
所有文件都swift结束的
main.swift文件是最先开始执行的文件，里面没有main函数。
println(可以是作何类型的变量或直接数);
var 声明变量
let 声明常量

let implicitDouble = 70.0;

声明变量时，可以使用 ：类型指定类型
var explicitDouble: Double = 70;

其它类型与字符串相连。
let oranges = 5;
let appleSummary = "I have \(oranges) apples."


数组及其遍历
var shoppingList = ["catfish", "water", "tulips", "blue paint"];
shoppingList[1] = "bottle of water";
for(var i=0; i<4; i++) {
    println("shoppingList[\(i)] = \(shoppingList[i])");
}
println("for each......");
for str in shoppingList {
    println("str=" + str);
}


键值对及其遍历
var occupations = ["Malcolm": "Captain", "Kaylee" : "Mechanic"];
occupations["Jayne"] = "Public Relations";
for (key,value) in occupations
{
    println(key+":"+value);
}


你可以一起使用if和let来处理值缺失的情况。有些变量的值是可选的。一个可选的值可能是一个具体的值或者是nil，表示值缺失。在类型后面加一个问号来标记这个变量的值是可选的。
var optionalName: String? = "John Appleseed"
//optionalName = nil
var greeting = "Hello!"
if let name = optionalName {//因为前面String后面有“？”所以可以为name赋值
    greeting = "Hello, \(name)"
    println(greeting)  //Hello, John Appleseed
}else {
    println(greeting)  //Hello!
}
如果optionalName的值不为nil如那执行 if后面大扩号的代码，否则执行esle后大扩号后面的代码
 

switch: 不用去使用break退出了。可以使用字符串类型
let vegetable = "red pepper"
var vegetableComment = "";
switch vegetable {
case "celery": //如果vegetable值为celery，则符合
      vegetableComment = "Add some raisins and make ants on a log."
case "cucumber", "watercress"://如果vegetable值为"cucumber”或”watercress"，则符合
      vegetableComment = "That would make a good tea sandwich."
case let x where x.hasSuffix("pepper")://如果vegetable值为red pepper，或最后单词为pepper则符合
      vegetableComment = "Is it a spicy \(x)"
default://如果前面都不符合，则符合
      vegetableComment = "Everything tastes good in soup."
}
println(vegetableComment);//Is it a spicy red pepper?

字典与遍历字典
let interestingNumbers = [
    "Prime": [2, 3, 5, 7, 11, 13],
    "Fibonacci": [1, 1, 2, 3, 5, 8],
    "Square": [1, 4, 9, 16, 25],
]
var largest = 0
for (kind, numbers) in interestingNumbers {
    for number in numbers {
        if number > largest {
            largest = number
        }
    }
}
println("largest -->  \(largest)");//largest --> 25