How to remove duplicate values from array

Question

I have one NSMutableArray which containing duplicates value e.g.[1,2,3,1,1,6]. I want to remove duplicates value and want new array with distinct values.

possible duplicate of [The best way to remove duplicate values from NSMutableArray in Objective-C?](http://stackoverflow.com/questions/1025674/the-best-way-to-remove-duplicate-values-from-nsmutablearray-in-objective-c) — Cody Gray - on strike, Apr 14 '11 at 10:26
see this too. i was answered. http://stackoverflow.com/questions/5281295/iphone-sdk-how-to-delete-duplicates-in-the-nsarray/5281491#5281491 — Splendid, Apr 14 '11 at 11:39
This SO question may help you http://stackoverflow.com/questions/1025674/the-best-way-to-remove-duplicate-values-from-nsmutablearray-in-objective-c — visakh7, Apr 14 '11 at 10:25
Does this answer your question? [The best way to remove duplicate values from NSMutableArray in Objective-C?](https://stackoverflow.com/questions/1025674/the-best-way-to-remove-duplicate-values-from-nsmutablearray-in-objective-c) — Cœur, Feb 06 '20 at 07:39

score 18 · Answer 1 · edited Jan 17 '14 at 12:42

18

two liner

NSMutableArray *uniqueArray = [NSMutableArray array];

[uniqueArray addObjectsFromArray:[[NSSet setWithArray:duplicateArray] allObjects]];

edited Jan 17 '14 at 12:42

Exception

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17

answered Aug 11 '11 at 09:23

REALFREE

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And use `NSOrderedSet` if you want the original order. – Cœur Feb 06 '20 at 07:38

score 3 · Answer 2 · edited Nov 24 '11 at 11:02

3

My solution:

array1=[NSMutableArray arrayWithObjects:@"1",@"2",@"2",@"3",@"3",@"3",@"2",@"5",@"6",@"6",nil];
array2=[[NSMutableArray alloc]init];
for (id obj in array1) 
{
    if (![array2 containsObject:obj]) 
    {
        [array2 addObject: obj];
    }
}
NSLog(@"new array is %@",array2);

The output is: 1,2,3,5,6..... Hope it's help you. :)

edited Nov 24 '11 at 11:02

eeerahul

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answered Nov 24 '11 at 10:46

GauravBoss

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hi can you tell me can i count no of duplicate element in array1 like 2 is coming in thrice time. – Gajendra Rawat Apr 28 '14 at 08:30

score 2 · Answer 3 · answered Apr 14 '11 at 10:24

I've made a category on NSArray with this method in :

- (NSArray *)arrayWithUniqueObjects {
    NSMutableArray *newArray = [NSMutableArray arrayWithCapacity:[self count]];

    for (id item in self)
        if (NO == [newArray containsObject:item])
            [newArray addObject:item];

    return [NSArray arrayWithArray:newArray];
}

However, this is brute force and not very efficient, there's probably a better approach.

score 0 · Answer 4 · edited Oct 08 '14 at 10:07

0

If you are worried about the order, check this solution

// iOS 5.0 and later
NSArray * newArray = [[NSOrderedSet orderedSetWithArray:oldArray] array];

edited Oct 08 '14 at 10:07

Pang

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answered Aug 23 '13 at 12:27

keen

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score 0 · Answer 5 · answered Dec 22 '14 at 04:45

0

NSSet approach is the best if you're not worried about the order of the objects

 uniquearray = [[NSSet setWithArray:yourarray] allObjects];

answered Dec 22 '14 at 04:45

Yogesh Kumar

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score 0 · Answer 6 · answered Apr 14 '11 at 10:25

If the order of the values is not important, the easiest way is to create a set from the array:

NSSet *set = [NSSet setWithArray:myArray];

It will only contain unique objects:

If the same object appears more than once in array, it is added only once to the returned set.

How to remove duplicate values from array

6 Answers6