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iOS Build a Simple iPhone App with Swift 2.0 Structs as Data Models Finishing Up Our Model

How to Prevent Fact Repetition


I was wondering if anyone knew a simple way to prevent the app from showing the same fact twice in a row or, rather, to ensure that every fact shown will be different from the fact that appeared previously.

I know this isn't necessary for the app to work, and that with a larger base of facts stored in the FactModel repetition would become less and less likely, I am just curious.

3 Answers

Anjali Pasupathy
Anjali Pasupathy
28,883 Points

Someone else asked a similar question regarding the background color. I provided a quick solution, and you could probably do something similar to prevent yourself from repeating fun facts.


I hope that helps!

Here is how I figured out how to do it. This way they don't repeat until all facts have been cycled through and then it just resets.

    func randomSequenceGenerator(min: Int, max: Int) -> () -> String {
        var numbers: [Int] = []
        return {
            if numbers.count == 0 {
                numbers = Array(min ... max)

            let index = Int(arc4random_uniform(UInt32(numbers.count)))
            return self.facts[numbers.remove(at: index)]

Then in ViewController change your factProvider. Make sure to set it from 0 to the count minus 1 as the first item in the array is 0.

    let factProvider = StrangeFacts().randomSequenceGenerator(min: 0, max: StrangeFacts().facts.count - 1)

Lastly in the ViewController you need to change funFactLabel.text in both the viewDidLoad as well as the IBAction.

        funFactLabel.text = factProvider()

Thank you!