Remove certain objects from NSMutableArray

Question

I have an NSMutableArray of objects which are of AdDetail class that hold a few properties (for eg. adId, adTitle, adPrice... etc). I want to remove only those objects which have adID = 0. How can I do that ?

There are many posts and samples to work out filtering array using NSPredicate.. some of below posts will help u.. http://stackoverflow.com/questions/7207050/searching-filtering-a-custom-class-array-with-a-nspredicate http://stackoverflow.com/questions/3386079/use-nspredicate-to-filter-by-object-attribute — vishy, Apr 03 '13 at 09:39

score 12 · Accepted Answer · answered Apr 03 '13 at 09:40

12

Perhaps something more elegant would suffice?

[array removeObjectsInArray:[array filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"adID == 0"]]];

answered Apr 03 '13 at 09:40

Zack Brown

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+1 I liked this one :) – Anoop Vaidya Apr 03 '13 at 09:44
can I negate this?(`[NSPredicate predicateWithFormat:@"adID != 0"]`) – Ankur Arya Apr 03 '13 at 10:12
Sure thing :] That would filter the array to remove objects where your adID is not equal to zero. – Zack Brown Apr 03 '13 at 10:21
one more thing adID is of class `NSInteger` due to that my app is crashing with `this class is not key value coding-compliant for the key adID.` – Ankur Arya Apr 03 '13 at 10:33
1

Is your `AdDetail` object a subclass of `NSManagedObject`? Perhaps changing your `NSInteger` to an `NSNumber` would be sufficient? – Zack Brown Apr 03 '13 at 10:51

Anoop Vaidya · Answer 2 · 2013-04-03T09:50:25.413

Using predicate

NSArray *filtered=[array filteredArrayUsingPredicate:[NSPredicate predicateWithFormat:@"(adId == 0)"]];

Using fastEnumeration:

NSMutableArray *newArray=[NSMutableArray new];
for(AdDetail adDetailObj in array){
    if(![[adDetailObj adId] isEqualToString:@"0"]){ //if these are strings, if NSInteger then directly compare using ==
       newArray[newArray.count]=adDetailObj;
   }
}

Now newArray contains all objects other than id=0

Rushi · Answer 3 · 2013-04-03T09:47:23.033

1

NSMutableArray *newArray = [NSMutableArray arrayWithArray:yourArray];

for (int i = 0; i < yourArray.count; i++)
{
     AdDetail *obj = (AdDetail *)[yourArray objectAtIndex:i];
     if (obj.adID == 0)
         [newArray removeObjectAtIndex:i];
}
yourArray = [newArray mutableCopy];

edited Apr 03 '13 at 09:47

answered Apr 03 '13 at 09:37

Rushi

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I think because I didn't put open and close bracket after if ;-) – Rushi Apr 03 '13 at 09:39
4

you are removing objects from the array while iterating, this will cause an error – tkanzakic Apr 03 '13 at 09:42
@tkanzakic: I am not removing while iterating :p – Anoop Vaidya Apr 03 '13 at 09:49
@tkanzakic: good point, Rushi: you have done edit with your answer but still it will cause an error.. – Ankur Apr 03 '13 at 10:15

iPatel · Answer 4 · 2013-04-03T09:51:45.230

1

for(i=0; i < myArray.count; i++)
{
  myClass = [myArray objectAtIndex:i];
  if([myClass.adID isEqualtoString:"0"])// if it it int/NSInteger the write myClass.adID==0
  {
            [myArray removeObjectAtIndex:i];
      i--;
  }
}

edited Apr 03 '13 at 09:51

answered Apr 03 '13 at 09:38

iPatel

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you are removing objects from the array while iterating, this will cause an error – tkanzakic Apr 03 '13 at 09:43

score 1 · Answer 5 · answered Apr 03 '13 at 09:40

1

Use following code :

int count = array.count;
for(i=0;i<count;i++){

     ADetail *adetail = [array objectAtIndex:i];
     if(adetail.adID = 0){

         [array removeObjectAtIndex:i];
          i--;

     }
     count = array.count;
}

answered Apr 03 '13 at 09:40

Payal

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i--; was music to my code. Thanks... :D – JgdGuy Dec 16 '14 at 07:05

score 0 · Answer 6 · answered Apr 03 '13 at 09:41

0

predicate = @"adID == 0";
newArray = [theArray filterUsingPredicate:aPredicate]

answered Apr 03 '13 at 09:41

msk

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Remove certain objects from NSMutableArray

6 Answers6