arc4random

I am making a game using Swift and SpriteKit where i move an object to random locations based on an array. The array that is made up of CGPoints: let easyArray = [CGPointMake(0,0), CGPointMake(126.6,0), CGPointMake(253.4,0), CGPointMake(0,197.5), CGPointMake(126.7,197.5), CGPointMake(253.4,197.5), CGPointMake(0,395), CGPointMake(126.7,395), CGPointMake(253.4,395)] I use this function to generate a random number: func randomNumber(maximum: UInt32) -> Int { var randomNumber = arc4random_uniform(maximum) while previousNumber == randomNumber { randomNumber = arc4random_uniform(maximum) }

This question already has an answer here: How do I shuffle an array in Swift? 25 answers When I grab an element from an array using the arc4random_uniform() method, the same element the array is often grabbed more than once. I am trying to make it so each element in the array is grabbed only once. The reason I'm trying to do this is so more than one cells in a UITableView don't have the same text. Here's the array for the text of the cells in the UITableView : var definitions = ["Used to carry the pharoah","Used to carry bodies as a ceremony","Had a flat deck to carry a farmer's treasure",

I've been racking my brain and searching here and all over to try to find out how to generate a random position on screen to spawn a circle. I'm hoping someone here can help me because I'm completely stumped. Basically, I'm trying to create a shape that always spawns in a random spot on screen when the user touches. override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) { let screenSize: CGRect = UIScreen.mainScreen().bounds let screenHeight = screenSize.height let screenWidth = screenSize.width let currentBall = SKShapeNode(circleOfRadius: 100) currentBall.position =

I know I can get a random number for example from 0 to 700 using: arc4random() % 362 But how can I get a random number in between for example 200 to 300? (arc4random() % 100) + 200 tpun11 Not to be picky, but I am pretty sure you have to add a number... if you want all the numbers from 200 to and including 300... use 200 + arc4random()%101; arc4random()%100 would give a random number from 0 to 99 so 300 would never occur... 来源： https://stackoverflow.com/questions/4059049/ios-random-numbers-in-a-range

I am trying to randomize numbers in an array. I am able to do that using arc4random() % [indexes count] My problem is - If an array consists of 20 items, every time the array shuffles, in a batch of 5, different number should appear. Example : first shuffle: 1,4,2,5,6. second shuffle: 7,12,9,15,3 -(IBAction)randomNumbers:(UIButton *)sender { int length = 10; // int length = [yourArray count]; NSMutableArray *indexes = [[NSMutableArray alloc] initWithCapacity:length]; for (int i=0; i<5; i++) [indexes addObject:[NSNumber numberWithInt:i]]; NSMutableArray *shuffle = [[NSMutableArray alloc]