What is the easiest way to generate random integers within a range in Swift?

Question

The method I\'ve devised so far is this:

func randRange (lower : Int , upper : Int) -> Int {
    let difference = upper - lower
    return Int(Float(rand(         


        

Answer 1

Here's a somewhat lighter version of it:

func randRange (lower: Int , upper: Int) -> Int {
    return lower + Int(arc4random_uniform(UInt32(upper - lower + 1)))
}

This can be simplified even further if you decide this function works with unsigned values only:

func randRange (lower: UInt32 , upper: UInt32) -> UInt32 {
    return lower + arc4random_uniform(upper - lower + 1)
}

Or, following Anton's (+1 for you) excellent idea of using a range as parameter:

func random(range: Range) -> UInt32 {
    return range.startIndex + arc4random_uniform(range.endIndex - range.startIndex + 1)
}