How do i get a random number from an array without repeating the same number twice in a row?

Question

Hello,

I am making a game 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)
}
    previousNumber = randomNumber
    return Int(randomNumber)
}

I used this to move the object based on the random number generated:

let greenEasy = randomNumberNew(9)
let moveSelector = SKAction.moveTo(easyArray[greenEasy], duration: 0)
selector.runAction(moveSelector)

I have done some reading online and found that the "While" condition should make it so that the same random number isn't generate twice in a row. But it still happens.

Can anyone please help me on how to make it so i don't get the same number twice in a row?

Thank you!

Answer 1 · 2015-03-05T19:53:09Z

March 5, 2015 7:53pm

You have to declare "previousNumber". The first time you access that function that variable doesn't exist. And also you need to do this outside the function, otherwise the while loop will never be executed because previousNumber will always be nil.

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josephsherratt

josephsherratt

How do i get a random number from an array without repeating the same number twice in a row?

1 Answer

Enara L. Otaegi

Enara L. Otaegi