Objective-c – Remove duplicate from NSMutableArray

noDuplicates = _personalHistory.personalHistory;

for (int i=[noDuplicates count]-1; i>0; i--) {
 if ([noDuplicates indexOfObject: [noDuplicates objectAtIndex: i] ] [noDuplicates removeObjectAtIndex: i];
}


for (PersonalHistory_artikels *e in _personalHistory.personalHistory) {
 if (! [noDuplicates containsObject:e]) {
 NSLog(@"Dubplicates");
 [noDuplicates addObject:e];
 }
}

< br />for (i=0; i<_personalHistory.personalHistory.count; i++) {
 PersonalHistory_artikels *test = [_personalHistory.personalHistory objectAtIndex:i];
 for (j=0; j<_personalHistory .personalHistory.count; j++) {
 PersonalHistory_artikels *test2 = [_personalHistory.personalHistory objectAtIndex:j];
 if (! [test.nieuwsTITLE_personal isEqual:test2.nieuwsTITLE_personal]) {
 NSLog(@"Add test = %@", test.nieuwsTITLE_personal);
 [noDuplicates addObject:test];
 }
 }
}

NSArray *hasDuplicates = /* (...) */;
NSArray *noDuplicates = [[NSSet setWithArray: hasDuplicates] allObjects]; 

I have a problem removing duplicate objects from the moving array.
I have tried these:

noDuplicates = _personalHistory.personalHistory;

for (int i=[noDuplicates count]-1; i>0; i--) {
 if ([noDuplicates indexOfObject: [noDuplicates objectAtIndex: i]] [noDuplicates removeObjectAtIndex: i];
}


for (PersonalHistory_artikels *e in _personalHistory.personalHistory) {
 if (![noDuplicates containsObject:e]) {
 NSLog(@"Dubplicates");
 [noDuplicates addObject:e];
 }
}


for (i=0; i<_personalHistory.personalHistory.count; i++) {
 PersonalHistory_artikels *test = [_personalHisto ry.personalHistory objectAtIndex:i];
 for (j=0; j<_personalHistory.personalHistory.count; j++) {
 PersonalHistory_artikels *test2 = [_personalHistory.personalHistory objectAtIndex:j];
 if (! [test.nieuwsTITLE_personal isEqual:test2.nieuwsTITLE_personal]) {
 NSLog(@"Add test = %@", test.nieuwsTITLE_personal);
 [noDuplicates addObject:test];
 }
 }
}

But none of the above gives me the correct array. The last one is the best, but it still shows duplicate values. Can someone help me solve this problem ?
Thank you very much.

Just convert the array to NSSet and then back. A set cannot be designed to be repeated.

Edit:

Please note that the collection does not have a sort order. Therefore, you can be cheaper and abandon the order, or perform a slightly more expensive operation but keep the order.

NSArray *hasDuplicates = /* (...) */;
NSArray *noDuplicates = [[NSSet setWithArray: hasDuplicates] allObjects];