CODEWITHSUNDEEP
iphoneios6nsmutablearray
Dev_iOS
Dev_iOS

Reputation: 251

Shuffled array uncaught exception

Im using four buttons and shuffle the button tag value to view different values on each click, Since i show the value of button from array, While am trying to shuffle the tag value i got following error.

  *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSMutableArray exchangeObjectAtIndex:withObjectAtIndex:]: index 16 beyond bounds [0 .. 3]'

My code for shuffling the array of tag value,

words = [[NSMutableArray alloc] initWithObjects:@"1", @"2", @"3",@"4", nil] ;

 NSUInteger count = [questar count];
for (NSUInteger i = 0; i < count; ++i) {
    // Select a random element between i and end of array to swap with.
    NSInteger nElements = count - i;
    NSInteger n = (arc4random() % nElements) + i;
    [words exchangeObjectAtIndex:i withObjectAtIndex:n];
}

What change should i made??Can any one help me to solve

Upvotes: 2

Views: 95

Answers (3)

Anusha Kottiyal
Anusha Kottiyal

Reputation: 3905

You have to select an image from quester first. You created the index n to take object from quester array no?

words = [[NSMutableArray alloc] initWithObjects:@"1", @"2", @"3",@"4", nil] ;

NSUInteger count = [questar count];
for (NSUInteger i = 0; i < count; ++i) 
{
  // Select a random element between i and end of array to swap with.
  NSInteger nElements = count - i;
  NSInteger n = (arc4random() % nElements) + i;

  currentImage = [questar objectAtIndex:n];

  [words replaceObjectAtIndex:i withObject:currentImage];
}

Or if you want to exchange within the array change count as :

NSUInteger count = [words count];

Upvotes: 1

tom
tom

Reputation: 19153

The following:

NSInteger nElements = count - i;
NSInteger n = (arc4random() % nElements) + i;

Should be changed to:

NSInteger nElements = count;
NSInteger n = (arc4random() % nElements);

Upvotes: 0

Ilanchezhian
Ilanchezhian

Reputation: 17478

[words exchangeObjectAtIndex:i withObjectAtIndex:n];

In the above statement, both i and n should have a value less than the words count (here it is 4). Else, you would get exception.

Upvotes: 0

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