.shuffle()和.shuffled()是Swift的一部分
原历史问题:
我如何随机或洗牌在Swift数组中的元素?例如,如果我的数组包含52张扑克牌,我想要洗牌数组以洗牌牌组。
.shuffle()和.shuffled()是Swift的一部分
原历史问题:
我如何随机或洗牌在Swift数组中的元素?例如,如果我的数组包含52张扑克牌,我想要洗牌数组以洗牌牌组。
当前回答
工作! !生物体是要洗牌的数组。
extension Array
{
/** Randomizes the order of an array's elements. */
mutating func shuffle()
{
for _ in 0..<10
{
sort { (_,_) in arc4random() < arc4random() }
}
}
}
var organisms = [
"ant", "bacteria", "cougar",
"dog", "elephant", "firefly",
"goat", "hedgehog", "iguana"]
print("Original: \(organisms)")
organisms.shuffle()
print("Shuffled: \(organisms)")
其他回答
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
}
这是最简单的方法。导入Gamplaykit到你的VC中,使用下面的代码。在Xcode 8中测试。
import GameplayKit
let array: NSArray = ["Jock", "Ellie", "Sue Ellen", "Bobby", "JR", "Pamela"]
override func viewDidLoad() {
super.viewDidLoad()
print(array.shuffled())
}
如果你想从数组中获得一个打乱的字符串,你可以使用下面的代码..
func suffleString() {
let ShuffleArray = array.shuffled()
suffleString.text = ShuffleArray.first as? String
print(suffleString.text!)
}
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])
}
}
}
Swift 3解决方案,遵循@Nate Cook的回答:(如果索引从0开始,请参阅下面的评论)
extension Collection {
/// Return a copy of `self` with its elements shuffled
func shuffle() -> [Generator.Element] {
var list = Array(self)
list.shuffleInPlace()
return list
} }
extension MutableCollection where Index == Int {
/// Shuffle the elements of `self` in-place.
mutating func shuffleInPlace() {
// empty and single-element collections don't shuffle
if count < 2 { return }
let countInt = count as! Int
for i in 0..<countInt - 1 {
let j = Int(arc4random_uniform(UInt32(countInt - i))) + i
guard i != j else { continue }
swap(&self[i], &self[j])
}
}
}
SWIFT 4
func createShuffledSequenceOfNumbers(max:UInt)->[UInt] {
var array:[UInt]! = []
var myArray:[UInt]! = []
for i in 1...max {
myArray.append(i)
}
for i in 1...max {
array.append(i)
}
var tempArray:[Int]! = []
for index in 0...(myArray.count - 1) {
var isNotFinded:Bool = true
while(isNotFinded){
let randomNumber = arc4random_uniform(UInt32(myArray.count))
let randomIndex = Int(randomNumber)
if(!tempArray.contains(randomIndex)){
tempArray.append(randomIndex)
array[randomIndex] = myArray[index]
isNotFinded = false
}
}
}
return array
}