EDIT:
I have two different arrays with some repeated strings and i want to create a new array with the only the unique strings.
For instance, take these two arrays:
NSArray *array1 = [[NSArray alloc] initWithObjects:@"a",@"b",@"c",nil];
NSArray *array2 = [[NSArray alloc] initWithObjects:@"a",@"d",@"c",nil];
// Result should be an array with objects "b", and "d"
// since they are the only two that are not repeated in the other array.
EDIT:
// Your starting arrays
NSArray *array1 = [[NSArray alloc] initWithObjects:@"a",@"b",@"c",nil];
NSArray *array2 = [[NSArray alloc] initWithObjects:@"a",@"d",@"c",nil];
// Create two new arrays that only contain the objects
// which are not in the other array:
NSMutableArray *uniqueElementsInArray1 = [array1 mutableCopy];
[uniqueElementsInArray1 removeObjectsInArray:array2];
NSMutableArray *uniqueElementsInArray2 = [array2 mutableCopy];
[uniqueElementsInArray2 removeObjectsInArray:array1];
// Combine the two arrays.
// Result contains objects @"b" and @"d":
NSArray *result = [uniqueElementsInArray1 arrayByAddingObjectsFromArray:uniqueElementsInArray2];
For this you just declare one another temp NSMutableArray . Retrieve whatever data u have from your original array say objectArray. Check whether the temp array have that or not and put it into the temp array. Just refer following code:
for(NSString *str in objectArray)
{
if(![tempArray containsObject:str])
{
[tempArray addObject:str];
}
}
After this u can continue to use tempArray or put tempArray into objectArray if you want to use objectArray further.I think this should work for you.
NSArray *array1 = @[@1,@2,@3,@4,@2,@3];
NSArray *array2 = @[@3,@4,@5,@6,@4,@6];
NSSet *set1 = [NSSet setWithArray:array1]; // [1,2,3,4]
NSSet *set2 = [NSSet setWithArray:array2]; // [3,4,5,6]
NSMutableSet *mSet1 = [set1 mutableCopy];
NSMutableSet *mSet2 = [set2 mutableCopy];
[mSet1 minusSet:set2]; // mSet1 = [1,2]
[mSet2 minusSet:set1]; // mSet2 = [5,6]
[mSet1 unionSet:mSet2]; // mSet1 = [1,2,5,6], only the unique elements.
// Now just put it in an immutable collections with a self-docu name...
NSArray *arrayOfUniqueness = [setOfUniqueElementsOnly allObjects];
NSSet *setOfObjsUniqueTo1 = [set1 objectsPassingTest:^BOOL(id _Nonnull obj, BOOL * _Nonnull stop) {
return ![set2 containsObject:obj];
}]; // [1,2]
NSSet *setOfObjsUniqueTo2 = [set2 objectsPassingTest:^BOOL(id _Nonnull obj, BOOL * _Nonnull stop) {
return ![set1 containsObject:obj];
}]; // [5,6]
NSMutableSet *oneSetToRuleThemAll = [NSMutableSet setWithSet:setOfObjsUniqueTo1];
// [1,2]
[oneSetToRuleThemAll unionSet:setOfObjsUniqueTo2]; // [1,2,5,6]
// Or as an array:
NSArray *anotherArrayOfUniqueness = [oneSetToRuleThemAll allObjects];
NSSet, but I would not seat this code opposite the Queen of England at a formal dinner -- it is inelegant):
NSMutableArray *mArray1 = [NSMutableArray new];
NSMutableArray *mArray2 = [NSMutableArray new];
NSIndexSet *uniqueIndexes1 = [array1 indexesOfObjectsPassingTest:^BOOL(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
return ![array2 containsObject:obj];
}]; // [0,1,4] (b/c @1 and @2 are unique to array1)
[uniqueIndexes1 enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL * _Nonnull stop) {
[mArray1 addObject:array1[idx]];
}]; // @[@1,@2,@2]
NSIndexSet *uniqueIndexes2 = [array2 indexesOfObjectsPassingTest:^BOOL(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
return ![array1 containsObject:obj];
}]; // [2,3,5] (b/c @5 and @6 are unique to array2)
[uniqueIndexes2 enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL * _Nonnull stop) {
[mArray2 addObject:array2[idx]];
}]; // @[@5,@6,@6]
NSArray *unionArray = [array1 arrayByAddingObjectsFromArray:array2];
// @[@1,@2,@2,@5,@6,@6]
NSArray *yetAnotherArrayOfUniqueness = [[NSSet setWithArray:unionArray] allObjects];
// @[@1,@2,@5,@6]
Not the questioner's question, but to get an array with duplicates removed (i.e., where each element is unique), similar magic can be done:
//given...
NSArray *arr1 = @[@"a", @"b", @"c"];
NSArray *arr2 = @[@"b", @"c", @"d"];
//...make a single array to rule them all:
NSArray *temp = [arr1 arrayByAddingObjectsFromArray:arr2];
//[a,b,c,b,c,d]
//Make an NSSet from the two:
NSSet *filterSet = [NSSet setWithArray:temp]; // Set has: a,b,c,d
//Finally, transmogrify that NSSet into an NSArray:
NSArray *arrayOfUniqueness = [filterSet allObjects]; // [a,b,c,d]
As per the Apple Docs (emphasis added):
+setWithArray: Creates and returns a set containing a uniqued collection of the objects contained in a given array.
UPDATE: And see here for a similar question: Remove all strings with duplicates in an NSArray
