How does one generate a random number in Apple's Swift language?

Question

I realize the Swift book provided an implementation of a random number generator. Is the best practice to copy and paste this implementation in one\'s own program? Or is t

Answer 1

Updated: August 06, 2020.

Swift 5.3

Let's assume we have an array:

let numbers: [Int] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

For iOS and macOS you can use system-wide random source in Xcode's framework GameKit. Here you can find GKRandomSource class with its sharedRandom() class method:

import GameKit

private func randomNumberGenerator() -> Int {
    let random = GKRandomSource.sharedRandom().nextInt(upperBound: numbers.count)
    return numbers[random]
}

randomNumberGenerator()

Also you can use a randomElement() method that returns a random element of a collection:

let randomNumber = numbers.randomElement()!
print(randomNumber)

Or use arc4random_uniform(). Pay attention that this method returns UInt32.

let generator = Int(arc4random_uniform(10))
print(generator)

And, of course, we can use a makeIterator() method that returns an iterator over the elements of the collection.

let iterator: Int = (1...10).makeIterator().shuffled().first!
print(iterator)

The final example you see here returns a random value within the specified range with a help of static func random(in range: ClosedRange) -> Int.

let randomizer = Int.random(in: 1...10)
print(randomizer)