If (变量==变量+ 5)

Question

我试图在我的场景中展示一枚奖牌，这取决于你的高分是基于目标的水平。

// Get Medal Colour
    if levelHighscore < goalScore {
        scoreMedal = SKSpriteNode(imageNamed: "noMedal")
    } else if levelHighscore == goalScore {
        scoreMedal = SKSpriteNode(imageNamed: "bronzeMedal")
    } else if levelHighscore > goalScore {
        scoreMedal = SKSpriteNode(imageNamed: "silverMedal")
    }

目前，我得到了高分，并将其与目标进行比较--如果它小于目标，请显示noMedal图像。如果与目标相等，则显示一个bronzeMedal，如果高分比目标显示silverMedal多5分，如果高分比目标高10分，则显示goldMedal。

对此进行了一段时间的尝试，由于某种原因，它在上面的设置中工作，但是当我编写

    // Get Medal Colour
    if levelHighscore == goalScore+5 {
        scoreMedal = SKSpriteNode(imageNamed: "silverMedal")
    } 

什么都没显示出来。

Answer 1

你需要你的比较才能像这样：

if levelHighscore < goalScore {
    scoreMedal = SKSpriteNode(imageNamed: "noMedal")
} else if levelHighscore >= goalScore + 10 {
    scoreMedal = SKSpriteNode(imageNamed: "goldMedal")
} else if levelHighscore >= goalScore + 5 {
    scoreMedal = SKSpriteNode(imageNamed: "silverMedal")
} else {
    scoreMedal = SKSpriteNode(imageNamed: "bronzeMedal")
}

重要的部分是先检查较高的值，然后检查较低的值。

为了使逻辑更加清晰，您可以将代码格式化如下：

if levelHighscore < goalScore {
    scoreMedal = SKSpriteNode(imageNamed: "noMedal")
} else {
    // We now know the score is greater or equal to goal
    // First see if it's hight enough for gold
    if levelHighscore >= goalScore + 10 {
        scoreMedal = SKSpriteNode(imageNamed: "goldMedal")
    } else {
        // Nope, maybe it's silver
        if levelHighscore >= goalScore + 5 {
            // Yes, it's 5 or more but less than 10 over so it's silver
            scoreMedal = SKSpriteNode(imageNamed: "silverMedal")
        } else {
            // No, it's less than 5 over leaving bronze
            scoreMedal = SKSpriteNode(imageNamed: "bronzeMedal")
        }
    }
}

Answer 2

取决于你的品味，我觉得这有点容易阅读和理解。

switch levelHighscore - goalScore {
case 0 ..< 5:     scoreMedal = SKSpriteNode(imageNamed: "bronzeMedal")
case 5 ..< 10:    scoreMedal = SKSpriteNode(imageNamed: "silverMedal")
case 10 ... .max: scoreMedal = SKSpriteNode(imageNamed: "goldMedal")
default:          scoreMedal = SKSpriteNode(imageNamed: "noMedal")
}

然而，@rmaddy的回答是非常好的。

Answer 3

这里有一些很好的答案，但我会选择做一些不同的。

首先，一系列具体的值有助于使用enum。

/// Raw values are the minimum for each Medal type.
/// For .none the raw value indicates any negative value
enum Medal: Int {
  case none   = -1
  case bronze = 0
  case silver = 5
  case gold   = 10
}

然后，我们添加一个初始化器，它需要一个分数和一个目标。我们还添加了一个返回image的SKSpriteNode属性

extension Medal {
  init(score: Int, goal: Int) {
    switch score - goal {
    case Medal.bronze.rawValue ..< Medal.silver.rawValue: self = .bronze
    case Medal.silver.rawValue ..< Medal.gold.rawValue  : self = .silver
    case Medal.gold.rawValue   ..< Int.max              : self = .gold
    default                                             : self = .none
    }
  }

  var image: SKSpriteNode {
    switch self {
    case .none  : return SKSpriteNode(imageNamed: "noMedal")
    case .bronze: return SKSpriteNode(imageNamed: "bronzeMedal")
    case .silver: return SKSpriteNode(imageNamed: "silverMedal")
    case .gold  : return SKSpriteNode(imageNamed: "goldMedal")
    }
  }
}

然后，您可以简单地这样做，以获得图像：

let image = Medal(score: 14, goal: 10).image

或

let image = Medal.bronze.image