Objective-C NSMutableArray

Question

I have filled a NSMutableArray with integer and string values from my database. The problem is that many values were inserted more than once. Using the following code I remove duplicate objects

for (id object in originalArray) {
    if (![singleArray containsObject:object]) {
        [singleArray addObject:object];
    }
}

Bus this works only if the objects are exactly the same between them. Is there a way to remove duplicates based on the integer value?

EDIT (from an OP's comment on a deleted answer)

I have some objects containing int and NSString. For example @"John 13", @"Mary 25", @"Luke 25", @"Joan 13". The NSMutableArray will contain all four names and duplicates of 13, 25. I want to remove the duplicates leaving 13 and 25 only once in the array. I do not care which names will be removed. Care only for the integer values to use them later.

The example that you provided in a comment to my answer (now deleted because it is obviously incorrect) is crucial to understanding the problem. It renders invalid pretty much every answer that you've got so far! Next time when you write a question, please add a small example. — Sergey Kalinichenko
– Sergey Kalinichenko, Commented Jan 26, 2013 at 11:46
That fact that you have the data is this awkward format probably means you could be doing things better elsewhere. E.g. If you're responsible for the creation of these strings, wouldn't you be better putting the number/name pairs into a dictionary or other data structure? — occulus
– occulus, Commented Jan 26, 2013 at 12:01
They are not all strings. The names are strings and the numbers are integers. I just wrote them all together as objects. For example "John 13" is an object in the array where "John" is the string value and "13" the integer value — J-K
– J-K, Commented Jan 26, 2013 at 14:31

Philippe Leybaert · Accepted Answer · 2013-01-26 11:41:42Z

0

If your elements are all NSNumber objects:

for (int i=0;i<array.count;i++) {
    for (int j=i+1;j<array.count;j++) {
        if ([array[i] isEqualToNumber:array[j]]) {
           [array removeObjectAtIndex:j--];
        }
    }
}

Or if all objects are either integer NSNumbers or NSStrings containing integer values:

for (int i=0;i<array.count;i++) {
    for (int j=i+1;j<array.count;j++) {
        if ([array[i] intValue] == [array[j] intValue]) {
           [array removeObjectAtIndex:j--];
        }
    }
}

edited Jan 26, 2013 at 11:41

answered Jan 26, 2013 at 11:33

Philippe Leybaert

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Comments

Ramy Al Zuhouri · Accepted Answer · 2013-01-26 11:36:36Z

0

Try this:

// singleArray is initially empty
for (id object in originalArray) 
{
    BOOL contains= YES;
    for( id single in singleArray)
    {
        if( [single integerValue]==[object integerValue] )
        {
            contains= NO;
            break;
        }
    }
    if(contains)
    {
        [singleArray addObject: object];  
    }
}

answered Jan 26, 2013 at 11:36

Ramy Al Zuhouri

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Comments

Bryan Chen · Accepted Answer · 2013-01-26 12:06:08Z

no test, tell me if it does not work. assuming objects in the array are string and format is "WORD NUMBER"

Boolean myEqual(const void *value1, const void *value2) {
    NSString *str1 = (__bridge NSString *)(value1);
    NSString *str2 = (__bridge NSString *)(value2);
    NSArray *arr1 = [str1 componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    NSArray *arr2 = [str2 componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    return [[arr1 lastObject] isEqual:[arr2 lastObject]];
}

CFHashCode myHash(const void *value) {
    NSString *str1 = (__bridge NSString *)(value);
    NSArray *arr1 = [str1 componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
    return [[arr1 lastObject] hash];
}


NSMutableArray *array = // your array;
CFSetCallBacks callBacks = kCFTypeSetCallBacks;
callBacks.equal = myEqual;
callBacks.hash = myHash;
CFMutableSetRef set = CFSetCreateMutable(NULL, [array count], &callBacks);
for (id obj in [array copy]) {  // copy so can modify the original array
    if (CFSetContainsValue(set, (__bridge const void *)(obj))) {
        [array removeObject:obj];
    } else {
        CFSetAddValue(set, (__bridge const void *)(obj));
    }
}

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