iOS Generating random numbers with Xcode 7 and Swift 2

[BigxMac]

I need to generate a random number and am using Xcode 7 beta with Swift 2. It appears the arc4random function no longer exists as well as the arc4random_uniform function. The options I have are arc4random_stir(), arc4random_buf(UnsafeMutablePointer<Void>, Int), and arc4random_addrandom(UnsafeMutablePointer<UInt8>, Int32). I can't find any docs on the functions and no comments in the header files give hints. Any help is appreciated

 

[abhibeckert]

arc4random() wasn't very good anyway, you should always have been using arc4random_buf.

It accepts a pointer to a location in memory, and a length for how much memory to overwrite with random data.

So define a variable, and give arc4random_buf the location in memory of that variable and a count of how many bytes the variable takes up:

var randomNum: UInt = 0
arc4random_buf(&randomNum, sizeof(UInt))

If you want a min/max value, then use the modulus operation:

func rand(min: UInt, max: UInt) -> UInt
{
  var randomNum: UInt = 0
  arc4random_buf(&randomNum, sizeof(UInt))

  return min + (randomNum % (max - min))
}

let blah = rand(10, 20)

 

[smirk]

I've been using arc4random_uniform in my Swift projects just fine. You need to import Foundation, though.