swift: 如何随机删除1到3个项目？

Question

我的代码只随机删除一枚硬币。我如何从 1 到 3 个硬币中随机取出？

@IBAction func endTurn(sender: UIButton!) {
    if coins.count > 0 { // @IBOutlet var coins: [UIButton]! (21 coins)
        let index: Int = Int(arc4random_uniform(UInt32(coins.count)))
        coins[index].hidden = true
        self.coins.removeAtIndex(index)
        if coins.isEmpty {
            println("GameOver")
        }
    }
}

Answer 1

试试这个

let numberToDelete = Int(arc4random_uniform(UInt32(3))) + 1

for i in 0..<numberToDelete{
    let indexToDelete = Int(arc4random_uniform(UInt32(coins.count)))
    coins.removeAtIndex(indexToDelete)
    if coins.isEmpty{
        break;
    }
}
if coins.isEmpty{
    println("GameOver")
}

Answer 2

对于随机数，我推荐这个 extension:

extension Int {
    static func random(range: Range<Int> ) -> Int {
        var offset = 0

        if range.startIndex < 0 {
            offset = abs(range.startIndex)
        }

        let min = UInt32(range.startIndex + offset)
        let max = UInt32(range.endIndex   + offset)

        return Int(min + arc4random_uniform(max - min)) - offset
    }
}

然后：

var i = Int.random(1...5)

swift: 如何随机删除1到3个项目？

swift: how to remove randomly from 1 to 3 items?

random

hidden

arc4random

swift