I need some help with an app. I need to make a random number generator for integers between zero and fifteen, which will then, depending on which number is created, push to a view with the corresponding number. This is how I want it to work
Push a button --> random number generator gives a number between 0 and 15 --> view pushes to another view that has been assigned the number that the random number generator gave.
Can anybody help me with the code? Thanks
arc4random() is the standard Objective-C random number generator function. It'll give you a number between zero and... well, more than fifteen! You can generate a number between 0 and 15 (so, 0, 1, 2, ... 15) with the following code:
NSInteger randomNumber = arc4random() % 16; Then you can do a switch or a series of if/else statements to push a different view controller:
UIViewController *viewController = nil; switch (randomNumber) { case 0: viewController = [[MyViewController alloc] initWithNibName:@"MyViewController" bundle:nil]; break; // etc ... } [self.navigationController pushViewController:viewController animated:YES]; Or rather, upon rereading the question, it would look like the following:
UIViewController *viewController = [[MyViewController alloc] initWithNibName:@"MyViewController" viewController.number = randomNumber; And you'd have an NSInteger property on the MyViewController subclass.
"The arc4random() function uses the key stream generator employed by the arc4 cipher, which uses 8*8 8 bit S-Boxes. The S-Boxes can be in about (2**1700) states. The arc4random() function returns pseudo-random numbers in the range of 0 to (2**32)-1, and therefore has twice the range of rand(3) and random(3)."You can use arc4random_uniform
NSUInteger r = arc4random_uniform(16); 
According to Apple, the best way is to use arc4random_uniform and pass the upper bound:
arc4random_uniform(16) From the docs:
arc4random_uniform() will return a uniformly distributed random number less than upper_bound. arc4random_uniform() is recommended over constructions like ``arc4random() % upper_bound'' as it avoids "modulo bias" when the upper bound is not a power of two.
int randomIndex = arc4random() % 14 + 1 ; // gives no .between 1 to 15 .. switch (randomIndex) { case 0 : push view 1 ; break; case 1: ... } 
In Swift 4.2, we don't have to call some "arc4random_uniform" function for creating random numbers, now we can just call a function "random(in:RANGE)".
//Create Random numbers Swift 4.2 //Int let randomInt = Int.random(in: 1...10) //Double let radomDouble = Double.random(in: 1...10) //Float let randomFloat = Double.random(in: 1...10) We can use the C function rand() for this:
This generates an integer between 1 and 30. Alternatively you can use the arc4random function like this:
int i = arc4random() % 30; NSLog(@"Random Number: %i", i); 
extension CGFloat { static func random() -> CGFloat { return CGFloat(arc4random()) / CGFloat(UInt32.max) } } 