闭包

funcsquare(number:Int) ->Int

{

    returnnumber * number

}

square(number:10)

letsquareClosuren =

{

   (number:Int) ->Intin

    returnnumber * number

}

squareClosuren(10)

//例子1

letdemo = {print("Hello 闭包")}

demo()

//计算两个数的商

letdivide =

    {

    (num1:Int,num2:Int) ->Intin

    returnnum1/num2

}

divide(100,10)

//闭包表达式  肯定是{}包括住的，

//{(partmeters) -> (return type)in

//statements

//}

funcgetScore(score:[Int], con : (Int)->Bool) -> [Int]

{

    //定义一个新的数组

    varnewScore:[Int] = [Int]()

    foriteminscore

    {

        ifcon(item)

        {

            newScore.append(item)

        }

    }

    returnnewScore

}

//--------------四种闭包简写方式---------------------------

//print(getScore(score: [65,75,85,95],con : {(s: Int)->Bool in return s>80}))

//print(getScore(score: [65,75,85,95],con : {(s: Int)in return s>80}))将尖头去掉

//print(getScore(score: [65,75,85,95],con : {s in return s>80}))省略参数类型

//print(getScore(score: [65,75,85,95],con : {s in  s>80}))  省略return关键字

//利用$0关键字

print(getScore(score: [65,75,85,95],con : { $0>80}))

letarr = [65,75,85,95]

print(arr.filter({$0 >60}))

arr.forEach

    {(s)inprint(s)}

funcmakeIncrementor(forIncrement amount:Int) -> () ->Int

{

    varrunningTotal =0

    funcincrementor() ->Int

    {

        runningTotal += amount

        returnrunningTotal

    }

returnincrementor

}

leta = makeIncrementor(forIncrement:10)

a()

a()

a()