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本文翻译自：How does one generate a random number in Apple's Swift language?
I realize the Swift book provided an implementation of a random number generator. 我意识到Swift书提供了随机数生成器的实现。 Is the best practice to copy and paste this implementation in one's own program? 最好的做法是将此实现复制并粘贴到自己的程序中吗？ Or is there a library that does this that we can use now? 或者是否有一个我们现在可以使用的库？
#1楼
参考：https://stackoom.com/question/1cjLl/如何在Apple的Swift语言中生成一个随机数
#2楼
I've been able to just use rand() to get a random CInt. 我已经能够使用rand()来获得一个随机的CInt。 You can make it an Int by using something like this: 您可以使用以下内容将其设为Int：
let myVar: Int = Int(rand())
You can use your favourite C random function, and just convert to value to Int if needed. 您可以使用自己喜欢的C随机函数，如果需要，只需将值转换为Int即可。
#3楼
You can do it the same way that you would in C: 你可以像在C中那样做：
let randomNumber = arc4random()
randomNumber is inferred to be of type UInt32 (a 32-bit unsigned integer) randomNumber被推断为类型为UInt32 （32位无符号整数）
#4楼
Swift 4.2+ Swift 4.2+
Swift 4.2 shipped with Xcode 10 introduces new easy-to-use random functions for many data types. 随Xcode 10一起提供的Swift 4.2为许多数据类型引入了易于使用的新随机函数。 You can call the random() method on numeric types. 您可以在数字类型上调用random()方法。
let randomInt = Int.random(in: 0..<6)
let randomDouble = Double.random(in: 2.71828...3.14159)
let randomBool = Bool.random()
#5楼
Use arc4random_uniform(n) for a random integer between 0 and n-1. 使用arc4random_uniform(n)表示0到n-1之间的随机整数。
let diceRoll = Int(arc4random_uniform(6) + 1)
Cast the result to Int so you don't have to explicitly type your vars as UInt32 (which seems un-Swifty). 将结果转换为Int，因此您不必将您的变量显式键入为UInt32 （这似乎是非Swifty）。
#6楼
Edit for Swift 4.2 编辑Swift 4.2
Starting in Swift 4.2, instead of using the imported C function arc4random_uniform(), you can now use Swift's own native functions. 从Swift 4.2开始，您现在可以使用Swift自己的本机函数，而不是使用导入的C函数arc4random_uniform（）。
// Generates integers starting with 0 up to, and including, 10
Int.random(in: 0 ... 10)
You can use random(in:) to get random values for other primitive values as well; 您可以使用random(in:)来获取其他原始值的随机值; such as Int, Double, Float and even Bool. 比如Int，Double，Float甚至Bool。
Swift versions < 4.2 Swift版本<4.2
This method will generate a random Int value between the given minimum and maximum 此方法将在给定的最小值和最大值之间生成随机Int值
func randomInt(min: Int, max: Int) -> Int {
return min + Int(arc4random_uniform(UInt32(max - min + 1)))
}
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