let shuffl = GKRandomSource.sharedRandom().arrayByShufflingObjects(in: arrayObject)

这是我所使用的:

func newShuffledArray(array:NSArray) -> NSArray {
    var mutableArray = array.mutableCopy() as! NSMutableArray
    var count = mutableArray.count
    if count>1 {
        for var i=count-1;i>0;--i{
            mutableArray.exchangeObjectAtIndex(i, withObjectAtIndex: Int(arc4random_uniform(UInt32(i+1))))
        }
    }
    return mutableArray as NSArray
}

在Swift 2.0中，GameplayKit可能会来拯救你!(iOS9或更高版本支持)

import GameplayKit

func shuffle() {
    array = GKRandomSource.sharedRandom().arrayByShufflingObjectsInArray(array)
}

这是如何在Swift 3.0中洗牌一个种子数组。

extension MutableCollection where Indices.Iterator.Element == Index {
    mutating func shuffle() {
        let c = count
        guard c > 1 else { return }


        for (firstUnshuffled , unshuffledCount) in zip(indices, stride(from: c, to: 1, by: -1)) {
            srand48(seedNumber)
            let number:Int = numericCast(unshuffledCount)
            let r = floor(drand48() * Double(number))

            let d: IndexDistance = numericCast(Int(r))
            guard d != 0 else { continue }
            let i = index(firstUnshuffled, offsetBy: d)
            swap(&self[firstUnshuffled], &self[i])
        }
    }
}

这是Nate为Swift 4实现的Fisher-Yates shuffle的一个版本 (Xcode 9)。

extension MutableCollection {
    /// Shuffle the elements of `self` in-place.
    mutating func shuffle() {
        for i in indices.dropLast() {
            let diff = distance(from: i, to: endIndex)
            let j = index(i, offsetBy: numericCast(arc4random_uniform(numericCast(diff))))
            swapAt(i, j)
        }
    }
}

extension Collection {
    /// Return a copy of `self` with its elements shuffled
    func shuffled() -> [Element] {
        var list = Array(self)
        list.shuffle()
        return list
    }
}

这些变化是:

约束indexes . iterator . element == Index现在是部分 的收集协议，并且不需要强加于 扩展了。 交换元素必须通过调用集合上的swapAt()来完成， 添加mutableccollection . swapat(_:_:)。 Element是Iterator.Element的别名。

你也可以使用通用交换函数，实现前面提到的Fisher-Yates:

for idx in 0..<arr.count {
  let rnd = Int(arc4random_uniform(UInt32(idx)))
  if rnd != idx {
    swap(&arr[idx], &arr[rnd])
  }
}

或者更简洁:

for idx in 0..<steps.count {
  swap(&steps[idx], &steps[Int(arc4random_uniform(UInt32(idx)))])
}