NSMutableArray inside setTitle - objective-c

Question

I've stored 4 unique numbers inside an NSMutableArray from 1-4. i've done that by using this code:
storeArray = [[NSMutableArray alloc] init];
BOOL record = NO;
int x;
for (int i=1; [storeArray count] < 4; i++) //Loop for generate different random values
{
x = arc4random() % 4;//generating random number
if(i==1)//for first time
{
[storeArray addObject:[NSNumber numberWithInt:x]];
}
else
{
for (int j=0; j<= [storeArray count]-1; j++)
{
if (x ==[[storeArray objectAtIndex:j] intValue])
record = YES;
}
if (record == YES)
{
record = NO;
}
else
{
[storeArray addObject:[NSNumber numberWithInt:x]];
}
}
}
I can then print the numbers out using storeArray[1] and so on.
the problem is i want to print the numbers inside this.
[option1 setTitle:questions[r][storeArray[0]] forState: UIControlStateNormal];
[option2 setTitle:questions[r][storeArray[1]] forState: UIControlStateNormal];
[option3 setTitle:questions[r][storeArray[2]] forState: UIControlStateNormal];
[option4 setTitle:questions[r][storeArray[3]] forState: UIControlStateNormal];
How can i do this?, cause i when i do this i get thread sigbrt error?

Answer 1

The problem is that your algorithm is faulty and when there are collisions because you are trying to keep the numbers unique, you don't record anything so your array might not always be the expected length. Actually there is a 91% chance of this happening in your case so it looks like it happens all the time.
Instead of trying to write your own algorithm, just use the existing classes. Simply use an NSSet to guarantee the uniqueness of the numbers in your array.
NSMutableSet *set = [[NSMutableSet alloc] init];
while(set.count < 4) {
int x = arc4random() % 4;
[set addObject:[NSNumber numberWithInteger:x]];
}
NSArray * storeArray = [set allObjects];