How do I randomize or shuffle the elements within an array in Swift? For example, if my array consists of 52 playing cards, I want to shuffle the array in o
The top answer is deprecated, so I took it upon myself to create my own extension to shuffle an array in the newest version of Swift, Swift 4.1 (Xcode 9):
extension Array {
// Non-mutating shuffle
var shuffled : Array {
let totalCount : Int = self.count
var shuffledArray : Array = []
var count : Int = totalCount
var tempArray : Array = self
for _ in 0..<totalCount {
let randomIndex : Int = Int(arc4random_uniform(UInt32(count)))
let randomElement : Element = tempArray.remove(at: randomIndex)
shuffledArray.append(randomElement)
count -= 1
}
return shuffledArray
}
// Mutating shuffle
mutating func shuffle() {
let totalCount : Int = self.count
var shuffledArray : Array = []
var count : Int = totalCount
var tempArray : Array = self
for _ in 0..<totalCount {
let randomIndex : Int = Int(arc4random_uniform(UInt32(count)))
let randomElement : Element = tempArray.remove(at: randomIndex)
shuffledArray.append(randomElement)
count -= 1
}
self = shuffledArray
}
}
[Array] -> [Array]
:let array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
print(array.shuffled)
This prints array
in a random order.
[Array] = [Array]
:var array = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
array.shuffle()
// The array has now been mutated and contains all of its initial
// values, but in a randomized shuffled order
print(array)
This prints array
in its current order, which has already been randomly shuffled.
Hopes this works for everybody, if you have any questions, suggestions, or comments, feel free to ask!