Objective C - Random XIB pick

Question

I have already posted another question about this, but no one seemed to know how to do this.

I want my app to pick a random XIB file for me, but dont use the ones that have already been randomly picked.

So heres what i have set up as of right now, it seems to work, but i have to keep pressing the button over and over until it finds one that hasnt be used.

-(IBAction)continueAction:(id)sender{

random = arc4random() % 2;
if (random == 0 && usedQ2 == 0) {
    Question_2 *Q2 = [[Question_2 alloc] initWithNibName:@"Question 2" bundle:nil];

    Q2.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [self presentModalViewController:Q2 animated:YES];
    [Q2 release];

}
else if (random == 1 && usedQ3 == 0) {
    Question_3 *Q3 = [[Question_3 alloc] initWithNibName:@"Question 3" bundle:nil];

    Q3.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [self presentModalViewController:Q3 animated:YES];
    [Q3 release];
}


}

So as you can see i have it pick from a random number, and from their find the one that it matches.

Then you can see i have another part of my if statement that is checking to make sure it hasn't been used before.

each NIB file has its own usedQ(whatever Q it is), and when that Nib file is loaded it puts that usedQ as 1.

I think i could get by doing this, but in order to get rid of the constant button pushing, i will have to put loads of else statements with more else statements in them.

I have also tried running the

random = arc4random() % 2;

in a while statement and a for statement, i hoped that it would keep looking for a number until one that hasn't be used was found with no luck.

Any help? thanks!

The [answer you received two days ago](http://stackoverflow.com/questions/6621141/objective-c-pick-random-nib-file/6621211#6621211) to [your previous question](http://stackoverflow.com/q/6621141/643383) seems to answer your question nicely. — Caleb, Jul 11 '11 at 04:38

Dancreek · Accepted Answer · 2011-07-11T04:30:39.257

2

Why don't you make a mutable array and populate it with the names of all your nibs.
Then read the count of the array and generate a random number in that range.
Extract the nib name at that index and remove it from the array.
repeat steps 2-3.

//Setup your list at an appropriate place 
NSMutableArray *nibs = [[NSMutableArray alloc] initWithObjects: @"One Nib", @"Another Nib", @"Last Nib", nil];

self.unusedNibs = nibs; //This should be a property you declare in your header.

[nibs release];
-(IBAction)continueAction:(id)sender{

int random = arc4random() % [self.unusedNibs count]; 
NSString *nibName = [self.unusedNibs objectAtIndex: random];

[self.unusedNibs removeObjectAtIndex: random];
//Load nib here.

}

edited Jul 11 '11 at 04:30

answered Jul 11 '11 at 04:16

Dancreek

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A set (`NSMutableSet`) would be better because the nibs have no order. – Jul 11 '11 at 04:24
NSSet may not be the best choice since you have no control over the randomness. You can call anyObject but there is no guarantee that the results of that will be sufficiently random. With an array you can be 100% sure that you are getting consistently random results since you have control over where in the array you are pulling objects from. – Dancreek Jul 11 '11 at 04:39
Sorry to bother you, but what kind of property would unusedNibs be set as? Thanks – Jacob Jul 11 '11 at 04:40
The term "property" refers to a variable set in your header. `@property (nonatomic, retain) NSMutableArray *unusedNibs;` – Dancreek Jul 11 '11 at 04:42

Objective C - Random XIB pick

1 Answers1