Generate random number of certain amount of digits

Question

Hy,

I have a very Basic Question which is :

How can i create a random number with 20 digits no floats no negatives (basically an Int) in Swift ?

Than

Answer 1

Swift 3 appzyourlifz's answer updated to Swift 3

Step 1:

extension Int {
init(_ range: Range ) {
    let delta = range.lowerBound < 0 ? abs(range.lowerBound) : 0
    let min = UInt32(range.lowerBound + delta)
    let max = UInt32(range.upperBound   + delta)
    self.init(Int(min + arc4random_uniform(max - min)) - delta)
    }
}

Step 2:

func randomNumberWith(digits:Int) -> Int {
    let min = Int(pow(Double(10), Double(digits-1))) - 1
    let max = Int(pow(Double(10), Double(digits))) - 1
    return Int(Range(uncheckedBounds: (min, max)))
}

Usage:

randomNumberWith(digits:4) // 2271
randomNumberWith(digits:8) // 65273410