标签：des blog http io ar for sp 数据 div
【适合对象】有一定编程基础的同学
【情景】边看边练，多练多学，自然成长。
【声明】此文章属于原创作品，未经授权，如非法转载，予以追究法律责任。 原文链接：http://www.cnblogs.com/codeAnimal/p/4041545.html
练习笔记：
1.var变量
var str = "Hello, playground" println(str)
2.if语句
var a = 20
if a > 10 {
println("if 语句，判断条件 无括号");
}
3.三元运算符
var sy = a > 80 ? "真":"假" println(sy)
4.指定数据类型
var a1:Int = 10 println(a1)
5.注释符号
//
6.数据类型
var inta:Int32 = 12 ; println(inta) var floata:Float32 = 10.0 ; println(floata)
7.控制流 for-in
let indi = [10,201,30]
var teamScore = 0
for score in indi {
if score > 50{
println(score)
}
}
打印结果：201
//练习1：特殊字符：//..表示 范围
var first = 0
for i in 0..3{
first += i
}
println(first)
//练习2：计算出 字典中，数字最大值 结果：456
let nums = ["prime":[45,456,1,3],"squ":[12,10,32] ]
var largest = 0
for(k,n) in nums{
for num in n{
if num > largest{
largest = num
}
}
}
println(largest)
8.switch语句 （注意：default,必须有）
let vege = "red peper"
var title = "default msg"
switch vege{
case "red":
title = "red"
case "red","peper":
title = "2";
case let y where y.hasSuffix("peper")://特殊用法
println(y)
title = "3"
default:
title = "ssss"
}
println(title)
9.while
var n = 2;
while n < 50 {
n = n*3
}
println(n)
10.计算字符串的长度 countElements
var s = "lljkjij " var l = countElements(s) println(l)
11.字符串相等 ==
var str1 = "i am liuqinghua"
var str2 = "i am liuqinghua"
if str1 == str2 {
println("result > "+"==")
}else{
println("result >"+"!=")
}
12.数据类型转换
let num1 = 3 let num2 = 0.1212 var pi = num1 + Int(num2) println(pi)
打印结果：3
13. Int? 可选类型
var strint = "123"
let convertedNum:Int? = strint.toInt() //不确定 strint是纯数字，还是字符串
println("\(convertedNum) result \(convertedNum!)")
// 为可选类型的变量设置nil值，表示没有任何值
var serverResponse:Int? = 404
serverResponse = nil
14.元组
//形式1. let httpError = (404,"fail") println(httpError.1) //形式2. let httpError2 = (status:404,descrip:"fail") println(httpError2.status)
15.数组
var shopList:String[] = ["Egg","Milk"]
//追加(append)
shopList.append("Flour")
println(shopList.count) //数组元素个数
//插入(insert)
shopList.insert("Maple",atIndex:shopList.count)
println(shopList)
//删除(removeAtIndex)
shopList.removeAtIndex(0)
println(shopList)
//数组的长度
shopList.count
//遍历1
for item in shopList
{
println(item)
}
//遍历2
for (index,value) in enumerate(shopList)
{
println("Item\(index+1):\(value)")
}
打印结果： index,下标（从0开始）
16.字典
var air:Dictionary<String,String> = ["A":"a","B":"b"]
//字典追加
air["C"] = "c"
println(air)
//字典删除元素 removeValueForKey
let isDel = air.removeValueForKey("A")
println(isDel) //"a" (被删除的值 )
println(air)
//字典长度 count属性
air.count
//字典遍历1
for (k,v) in air
{
println(k+":" + v)
}
//字典遍历2：分别遍历keys和values
for key in air.keys
{
println(key)
}
for value in air.values
{
println(value)
}
//把键转换成数组
let airKey = Array(air.keys)
println(airKey)
17.函数
func sumOf(nums:Int...) -> Int{
var sum = 0
var j = 0
for n in nums{
sum += n
j++
}
return sum/j
}
//调用方法
var code = sumOf(20,20,20)
println(code)
18.类
class Test{
//声明变量
var num:Int = 0
var name:String
//构造函数
init(name:String){
self.name = name;
}
//自定义方法，返回String
func simple() -> String{
return name;
}
}
var test = Test(name:"liuqinghua")
var name = test.simple()
println(name)
打印结果：liuqinghua
标签：des blog http io ar for sp 数据 div
原文地址：http://www.cnblogs.com/codeAnimal/p/4041545.html
