.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
斯威夫特4 在for循环中洗牌数组的元素，其中i是混合比例
var cards = [Int]() //Some Array
let i = 4 // is the mixing ratio
func shuffleCards() {
for _ in 0 ..< cards.count * i {
let card = cards.remove(at: Int(arc4random_uniform(UInt32(cards.count))))
cards.insert(card, at: Int(arc4random_uniform(UInt32(cards.count))))
}
}
或者扩展为Int
func shuffleCards() {
for _ in 0 ..< cards.count * i {
let card = cards.remove(at: cards.count.arc4random)
cards.insert(card, at: cards.count.arc4random)
}
}
extension Int {
var arc4random: Int {
if self > 0 {
print("Arc for random positiv self \(Int(arc4random_uniform(UInt32(self))))")
return Int(arc4random_uniform(UInt32(self)))
} else if self < 0 {
print("Arc for random negotiv self \(-Int(arc4random_uniform(UInt32(abs(self)))))")
return -Int(arc4random_uniform(UInt32(abs(self))))
} else {
print("Arc for random equal 0")
return 0
}
}
}
其他回答
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)
}
斯威夫特4 在for循环中洗牌数组的元素，其中i是混合比例
var cards = [Int]() //Some Array
let i = 4 // is the mixing ratio
func shuffleCards() {
for _ in 0 ..< cards.count * i {
let card = cards.remove(at: Int(arc4random_uniform(UInt32(cards.count))))
cards.insert(card, at: Int(arc4random_uniform(UInt32(cards.count))))
}
}
或者扩展为Int
func shuffleCards() {
for _ in 0 ..< cards.count * i {
let card = cards.remove(at: cards.count.arc4random)
cards.insert(card, at: cards.count.arc4random)
}
}
extension Int {
var arc4random: Int {
if self > 0 {
print("Arc for random positiv self \(Int(arc4random_uniform(UInt32(self))))")
return Int(arc4random_uniform(UInt32(self)))
} else if self < 0 {
print("Arc for random negotiv self \(-Int(arc4random_uniform(UInt32(abs(self)))))")
return -Int(arc4random_uniform(UInt32(abs(self))))
} else {
print("Arc for random equal 0")
return 0
}
}
}
swift 4.2有两个方便的功能:
// shuffles the array in place
myArray.shuffle()
and
// generates a new array with shuffled elements of the old array
let newArray = myArray.shuffled()
在Swift 4.2中，现在有一个可变shuffle和不可变shuffle的方法。你可以在这里阅读更多关于随机生成和数组的东西。
这是我所使用的:
import GameplayKit
extension Collection {
func shuffled() -> [Iterator.Element] {
let shuffledArray = (self as? NSArray)?.shuffled()
let outputArray = shuffledArray as? [Iterator.Element]
return outputArray ?? []
}
mutating func shuffle() {
if let selfShuffled = self.shuffled() as? Self {
self = selfShuffled
}
}
}
// Usage example:
var numbers = [1,2,3,4,5]
numbers.shuffle()
print(numbers) // output example: [2, 3, 5, 4, 1]
print([10, "hi", 9.0].shuffled()) // output example: [hi, 10, 9]
