iOS - Get unique values from multiple arrays using the same order

Question

I have 2 arrays:

Array one: (@"26", @"26", @"25", @"25", @"3", @"3", @"4", @"4")

Array two: (@"sticker", @"sticker", @"sticker", @"sticker", @"sticker", @"frame", @"frame", @"frame")

Edit

These 2 arrays are connected like this:

26 - sticker
26 - sticker
25 - sticker
25 - sticker
3 - frame
3 - frame
4 - frame
4 - frame

I'm getting unique value in array one and putting it in another array like this:

NSArray *uniqueArrayOne = [[NSSet setWithArray:arrayOne] allObjects];

So uniqueArrayOne looks like this:

(26, 25, 3, 4)

I want uniqueArrayTwo to also be arrange like how uniqueArrayOne was arranged. I want uniqueArrayTwo to look like this:

(sticker, sticker, frame, frame)

What do I do?

Edit

Here is another example:

Array one: (@"TONY", @"SANSA", @"BILL", @"BILL", @"STEVE", @"STEVE")

Array two: (@"STARK", @"STARK", @"GATES", @"GATES", @"JOBS", @"JOBS")

The results should be like this:

uniqueArrayOne :(TONY, SANSA, BILL, STEVE)

uniqueArrayTwo :(STARK, STARK, GATES, JOBS)

uniqueArrayTwo is arrange depending on uniqueArrayOne.

You have to clarify that you want the second instance of each number form the first array. It's not at all obvious from the question. — Avi, Jul 24 '16 at 09:04
Actually, you aren't at all consistent. Perhaps you left out a `frame`? — Avi, Jul 24 '16 at 09:05
Possible duplicate of [How to turn an NSArray of strings into an array of unique strings, in the same order?](http://stackoverflow.com/questions/4209823/how-to-turn-an-nsarray-of-strings-into-an-array-of-unique-strings-in-the-same-o) — Fahim Parkar, Jul 24 '16 at 09:15
@FahimParkar I already looked at that answer. It is similar but not a duplicate. — imstillalive, Jul 24 '16 at 09:19
I agree with @fahim-parkar, the answers on that question get you most of the way there. (I wouldn't say quite 99%.) — Avi, Jul 24 '16 at 09:49
Why don't you use a `NSArray` of `NSDictionary` instead of `arrayOne` and `arrayTwo` => `NSArray *array = @[@{@"Name:"@"Tony", @"FamilyName":@"Stark"},@{@"Name:"@"Sansa", @"FamilyName":@"Stark"}, @{@"Name:"@"Bill", @"FamilyName":@"Gates"} ]`? You are trying to synchronize the items on two separates array where putting it in only may be clearer. — Larme, Jul 25 '16 at 12:12

score 1 · Answer 1 · answered Jul 24 '16 at 14:21

I would solve it this way

- (void)uniqueArrayFinder
{
    NSArray *array1 = [[NSArray alloc] initWithObjects:
                       @"TONY", @"SANSA", @"BILL", @"BILL", @"STEVE", @"STEVE",nil];
    NSArray *array2 = [[NSArray alloc] initWithObjects:
                       @"STARK", @"STARK", @"GATES", @"GATES", @"JOBS", @"JOBS",nil];

    NSMutableArray *combinedArray = [[NSMutableArray alloc] init];

    for (int i=0; i<[array1 count];i++)
    {
        NSString *arrayVal1 = [array1 objectAtIndex:i];
        NSString *arrayVal2 = [array2 objectAtIndex:i];
        NSString *combinedStr = [NSString stringWithFormat:@"%@ %@", arrayVal1, arrayVal2];
        [combinedArray addObject:combinedStr];
    }

    //this gives uniqe values
    NSSet *uniqueEvents = [NSSet setWithArray:combinedArray];
    [combinedArray removeAllObjects];
    [combinedArray addObjectsFromArray:[uniqueEvents allObjects]];

    NSLog(@"combinedArray: %@ ...", combinedArray);


}

Output:

combinedArray: (
    "STEVE JOBS",
    "TONY STARK",
    "SANSA STARK",
    "BILL GATES"
) ...

score 1 · Answer 2 · answered Jul 24 '16 at 17:51

You can achieve the desired result with the following,

NSArray *arr1 = @[@"26", @"26", @"25", @"25", @"3", @"3", @"4", @"4"];
NSArray *arr2 = @[@"sticker", @"sticker", @"sticker", @"sticker", @"sticker", @"frame", @"frame", @"frame"];

NSDictionary *dict = [NSDictionary dictionaryWithObjects:arr2 
                                   forKeys:arr1];

NSArray *distinctArr1 = [[NSOrderedSet orderedSetWithArray:arr1] array];

NSMutableArray *distinctArr2 = [NSMutableArray array];
for (NSString *num1 in distinctArr1) {
    [distinctArr2 addObject:dict[num1]];
}
// Your distinctArr2 is sorted based on distinctArr1's indices

score 0 · Answer 3 · answered Jul 24 '16 at 10:13

Try this one.

NSArray *arrayOne = @[@"TONY", @"SANSA", @"BILL", @"BILL", @"STEVE", @"STEVE"];
NSArray *arrayTwo = @[@"STARK", @"STARK", @"GATES", @"GATES", @"JOBS", @"JOBS"];

NSArray *uniqueArrayOne = [[NSSet setWithArray:arrayOne] allObjects];
NSMutableArray *uniqueArrayTwo = [NSMutableArray array];

[uniqueArrayOne enumerateObjectsUsingBlock:^(id  _Nonnull obj1, NSUInteger idx, BOOL * _Nonnull stop) {
    NSUInteger found = [arrayOne indexOfObjectPassingTest:^BOOL(id  _Nonnull obj2, NSUInteger idx, BOOL * _Nonnull stop) {
        return [(NSString *)obj2 isEqualToString:(NSString *)obj1];
    }];
    [uniqueArrayTwo addObject:[arrayTwo objectAtIndex:found]];
}];

NSLog(@"%@, %@", uniqueArrayOne, uniqueArrayTwo);

iOS - Get unique values from multiple arrays using the same order

3 Answers3