How to Prevent Fact Repetition

Question

Hi, 
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.

Anjali Pasupathy · Accepted Answer

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.
https://teamtreehouse.com/community/non-repeating-random-number-with-uicolor (https://teamtreehouse.com/community/non-repeating-random-number-with-uicolor)
I hope that helps!

Brandon Mahoney · Answer

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.
```swift
    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.
swift
    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.
swift
        funFactLabel.text = factProvider()

Sonia Feldman · Answer

Thank you!

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Sonia Feldman

Sonia Feldman

How to Prevent Fact Repetition

3 Answers

Anjali Pasupathy

Anjali Pasupathy

Brandon Mahoney

Brandon Mahoney

Sonia Feldman

Sonia Feldman

Anjali Pasupathy

Anjali Pasupathy