NSMutable array automatically replacing previous value

Question

Array replacing previously added object.

array=[[NSMutableArray alloc]init];

NSNumber * index;

AppDelegate * delegate=(AppDelegate *)[[UIApplication sharedApplication]delegate];
if(delegate.counter!=NumberImages.count)
{
    NSLog(@"%d",delegate.counter);

    imgview.tag=delegate.counter;

    NSLog(@"%ld",(long)imgview.tag);

    index=[[NSNumber alloc]initWithInt:[[firstNo objectAtIndex:imgview.tag]integerValue]];

    //int a=[[firstNo objectAtIndex:imgview.tag]integerValue];

    NSLog(@"%@",index);

    NSLog(@"%@",array);
}

[array addObject:index];

NSLog(@"%@",array);

Problem is that as I insert the object, previously existing object gets replaced.

How may I do this?

u r adding value only once. so there should be one value only. where is the issue? Is this code in for loop or something? — Baby Groot
– Baby Groot, Commented Jul 16, 2013 at 11:35

soryngod · Accepted Answer · 2013-07-16 11:36:31Z

1

Here is the problem:

 array=[[NSMutableArray alloc]init];

Move that into the

-(void)viewDidLoad

or

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

and it should be fixed.

Because you are calling the same function over and over again the array is reinitialized and it will only have 1 value.

answered Jul 16, 2013 at 11:36

soryngod

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bluehallu · Accepted Answer · 2013-07-16 11:37:24Z

1

An array, by definition, has one value at each index. If you add 2 objects in the same index, the last insertion overwrites all the past ones. Also, if you create the array each time, every array "deletes" the old one. In fact, you're leaking memory by not releasing it.

edited Jul 16, 2013 at 11:37

answered Jul 16, 2013 at 11:30

bluehallu

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2 Comments

soryngod Over a year ago

as you can see he is adding a value so the default behavior of an NSMutableArray would be creating a list. index is the value not an actual index of the array.

soryngod Over a year ago

@Vasu Maybe because you alloc init the array each time.

Prasad G · Accepted Answer · 2013-07-16 13:03:45Z

0

if (!array) {
         array=[[NSMutableArray alloc]init];
}

I think it will be helpful to you.

answered Jul 16, 2013 at 13:03

Prasad G

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