Swift 学习小结：简单值 及流程控制

import UIKit

var str = "Hello,playground"
//简单值
//let 声明常量  var 声明变量
var value = 123;
var i:Int = 0;
var num = 0;

var maVariable = 42;
maVariable = 50;
let myConstant = 42;

let implicitInteger = 70
let implicitDouble = 70.0
let explicitDoublie:Double = 70

let label = "This width is"
let width = 94
let widthLabel = label + String(width)

let apples = 3
let oranges = 5
let applesSummary  = "I have \(apples) apples"
let orangesSummary = "I have \(oranges) oranges"

var shoppingList = ["catfishi","water","tulips","blue paint"]
shoppingList[1] = "bottle of water"
var occupations = [
"Malcolm":"Captain","Kaylee":"Mechanic"
]
occupations["Jsyne"] = "Public Relations"

let emptyaraay = String[]()
let emptyDictionary =  Dictionary<String,Float>()

shoppingList = []

//流程控制
switch ("abc")
{
case "123":
    println("123");
case "456","abc":
    println("123 abc")
default:
    println("没有找到合适的匹配")
}
var i:Int = 0;
while(i<10)
{
    i++;
    println(i);
}
do
{
    i--;
    println(i);
}while (i>0);
for index in 1...5
{
    println("index = \(index)");
}
let indicidualscores = [75,43,103,87,12]
var teamSore = 0
for  score in indicidualscores {
    if score > 50 {
        teamSore += 3;
    
    }else {
        teamSore += 1;
    
    }
}
teamSore

var optionalString:String? = "Hello"
optionalString == nil
var optionalName:String? = "John Appleseed"
var greeting = "Hello!"
if let name  = optionalName{

     greeting = "hello,\(name)"

}

let  vegetable = "red pepper"
switch  vegetable {
 case "celery":
    let  vegetableCommment = "Add some raisins and make ant on a log"
 case "cucumber","watercress":
    let vegetablComment = "That would make a good tea sandwich"
 case let x where x.hasSuffix("pepper"):
    let vegetableCommment = "Is it a spicy \(x)"
default:
    let vegetableComment = "Everything tastes good in soup"
}

let interestingNumbers = [
 "Prime":[2,3,5,7,11,13],"Fibonnacci":[1,1,2,8],"Square":[1,4,9,16,25],]
var largrst = 0
for(kind,numbers) in interestingNumbers{
    for number in numbers{
        if  number > largrst{
        
            largrst = number
        
        }
      
    }

}
largrst

var n = 2
while n < 100 {
 n = n * 2
}
n

var  m =  2
do {

   m =  m * 2

} while m < 100
m

var  firstForLoop = 0
for i in 0..3 {
firstForLoop += i
}
firstForLoop

var secondForLoop = 0
for  var i = 0; i < 3; ++i {
  secondForLoop += i



}
secondForLoop