如何在數字間隔的條件下製作一個「for」循環Xcode Swift2

嘿，我想弄清楚如何在45分鐘內打入球門的情況下計算出足球進球數，但是func有一些輕微的錯誤與迅速2.任何幫助？謝謝！代碼：如何在數字間隔的條件下製作一個「for」循環Xcode Swift2

var barcelonavsRealMadrid1goals : [String : Int] = ["barcelonaGoal1":21,"RealMadridGoal2":23,"barcelonaGoal3":24,"RealMadridGoal4":27] 


    func Run() { 
    var goalCount=0 
    for (goal,numbers) in barcelonavsRealMadrid1goals{ 
     for(var number in numbers) { 
      if(number < 45) 
      goalCount++ 

     } 
    }

來源

2016-02-26 Hunter

什麼是錯誤，具體？ –

爲什麼你使用這種複雜的方法？你正在導致語法錯誤 –

哦，好的，謝謝你的擡頭 – Hunter

你有一個額外for..in循環在那裏，是沒有必要的：

for(var number in numbers) {

它也有一個無關的(和)圍繞它

for var number in numbers {

這裏是你的代碼的工作版本：

var barcelonavsRealMadrid1goals = ["barcelonaGoal1":21,"RealMadridGoal2":23,"barcelonaGoal3":24,"RealMadridGoal4":27] 

func run() -> Int { // functions should start with lower case 
    var goalCount=0 
    for (_,numbers) in barcelonavsRealMadrid1goals where numbers < 45 { 
    goalCount++ 
    } 
    return goalCount 
} 

let goalCount = run()

和功能的方法是這樣的：

let goalCount = goals.reduce(0) { 
    if $0.1.1 < 45 { 
    return $0.0 + 1 
    } 
    return $0.0 
}

並提供瞭解釋：

var goals = [ 
    "barcelonaGoal1" :21, 
    "RealMadridGoal2":23, 
    "barcelonaGoal3" :24, 
    "RealMadridGoal4":27, 
    "RealMadridGoal5":45] 

// For our use reduce takes an initial value of Int 
// and a combine function of type 
// (Int, (String, Int)) -> Int 
// 
// Reduce will call the closure once with 
// each value in the map and the previous return value 
let goalCount = goals.reduce(0, combine: { 
    (initial:Int, current:(key:String, value:Int)) -> Int in 
    var currentCount = initial 

    // print to show input and output of closure 
    print("parameters:(\(initial), (\"\(current.key)\", \(current.value)))", terminator:", ") 
    defer { 
    print("return:\(currentCount)") 
    } 
    // end printing 

    if current.value < 45 { 
    ++currentCount // add 1 to the running total 
    return currentCount 
    } 
    return currentCount 
}) 

// console output: 
// parameters:(0, ("barcelonaGoal1", 21)), return:1 
// parameters:(1, ("RealMadridGoal4", 27)), return:2 
// parameters:(2, ("RealMadridGoal5", 45)), return:2 
// parameters:(2, ("RealMadridGoal2", 23)), return:3 
// parameters:(3, ("barcelonaGoal3", 24)), return:4

來源

2016-02-26 12:38:08 ColGraff

很高興幫助！如果你學習它，功能性的方式非常棒，它可以真正簡化你的代碼。函數'map'，'filter'和'reduce'非常強大。 – ColGraff

@Hunter我在關閉時添加了更多的細節，所以你可以研究它，如果你想。 – ColGraff

哇看起來很棒！謝謝！ – Hunter

爲你解決是問題，嘗試使用在迅速推出功能編程：

var barcelonavsRealMadrid1goals : [String : Int] = ["barcelonaGoal1":95,"RealMadridGoal2":23,"barcelonaGoal3":24,"RealMadridGoal4":27] 

var filtered = barcelonavsRealMadrid1goals.filter { (team:String, minute:Int) -> Bool in 

    var state = false 
    if (minute > 45) 
    { 
     return true 
    } 
    return state 
} 


let totalCount = filtered.count

來源

2016-02-26 12:30:43

試試這個方法。

func Run() { 
    var goalCount=0 
    for (_, score) in barcelonavsRealMadrid1goals { 
      if(score < 45) { 
       goalCount++ 
      } 
     } 
    print(goalCount) 
}

來源

2016-02-26 12:40:43

如何在數字間隔的條件下製作一個「for」循環Xcode Swift2

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