ios - 获取唯一对象数组

Question

我有一个日期数组:

"2014-05-09 23:00:00 +0000",
"2014-05-09 23:00:00 +0000",
"2014-05-09 23:00:00 +0000",
"2014-05-09 23:00:00 +0000",
"2014-05-09 23:00:00 +0000",
"2014-05-09 23:00:00 +0000",
"2014-05-11 23:00:00 +0000",
"2014-05-11 23:00:00 +0000"

我想把这个数组拆分成两个不同的，放在一个数组中，

我想要的结果:

(
    "2014-05-09 23:00:00 +0000",
    "2014-05-09 23:00:00 +0000",
    "2014-05-09 23:00:00 +0000",
    "2014-05-09 23:00:00 +0000",
    "2014-05-09 23:00:00 +0000",
    "2014-05-09 23:00:00 +0000",

),
    (
    "2014-05-11 23:00:00 +0000",
    "2014-05-11 23:00:00 +0000"
)

---

这是我尝试过的:

self.tempDatesArray - array of dates (unique)
tempArray - array of all dates

self.tempDatesArray = [[[NSOrderedSet orderedSetWithArray:[self.tempDatesArray copy]] array] mutableCopy]; // i'm getting all the unique dates from array

---

if (self.tempDatesArray.count > 0){
                for (int j=0;j<self.tempDatesArray.count;j++){
                    if (tempArray[i] == self.tempDatesArray[j]){

                        [tempArray2 addObject:tempArray[i]]; // temp array

                        if (j++){

                            NSLog(@"i is %i",i);

                            [resultArray addObject:tempArray2];

                            NSLog(@"test %@",self.sectionsArray);

                            tempArray2 = [@[] mutableCopy];
                            }
                        }
                    }
            }

我的结果是:

(
        "2014-05-09 23:00:00 +0000",
        "2014-05-09 23:00:00 +0000",
        "2014-05-09 23:00:00 +0000",
        "2014-05-09 23:00:00 +0000",
        "2014-05-09 23:00:00 +0000",
        "2014-05-09 23:00:00 +0000",
        "2014-05-11 23:00:00 +0000"
    ),
        (
        "2014-05-11 23:00:00 +0000"
    )

因此我有点沮丧，有人可以指导我正确的方向吗？

Answer 1

另一种方法:

NSMutableArray *result = [NSMutableArray new];
[[arrayOfDates valueForKeyPath:@"@distinctUnionOfObjects.self"] enumerateObjectsUsingBlock:^(NSDate *date, NSUInteger idx, BOOL *stop) {

    NSIndexSet *indexSet = [arrayOfDates indexesOfObjectsPassingTest:^BOOL(NSDate *d, NSUInteger idx, BOOL *stop) {
        return [d isEqual:date];
    }];

    [result addObject:[arrayOfDates objectsAtIndexes:indexSet]];
}];