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iOS

How to avoid repeating facts

How can I generate a random non-repeating number? To avoid showing the same fact twice (until all facts have been shown first)

The current code sometimes repeats number (hence repeating duplicate facts before going through the whole array:

import GameKit

struct QuoteProvider {
    let quoteArray = [quote1, quote2, quote3, quote4, quote5]
    func randomQuote() -> Quote { 
        let randomNumber = GKRandomSource.sharedRandom().nextInt(upperBound: quoteArray.count)
        return quoteArray[randomNumber]
    }
}

1 Answer

Ty Schenk
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Ty Schenk
iOS Development Techdegree Graduate 16,269 Points

Hello,

I think something like this would work great for what you are looking for. I made a few adjustments so please change those to reflect your code.

var quoteArray: [String] = ["quote1", "quote2", "quote3", "quote4", "quote5"]
var usedQuoteArray: [String] = []

func randomQuote() -> String {
    if quoteArray.count == 0 {
        resetQuotes()
    }

    // Get Random Number
    let randomNumber = GKRandomSource.sharedRandom().nextInt(upperBound: quoteArray.count)

    // Save Quote to constant
    let quote = quoteArray[randomNumber]

    // Add Quote tp usedQuoteArray
    usedQuoteArray.append(quoteArray[randomNumber])

    // Remove from Available
    quoteArray.remove(at: randomNumber)

    return quote
}

func resetQuotes() {
    for quote in usedQuoteArray {
        quoteArray.append(quote)
    }
}