CODEWITHSUNDEEP
objective-cdatesortingnsdate
zhuber
zhuber

Reputation: 5524

Get all dates of same day from array

Lets say I have NSMutableArray of different dates. Dates are represented in UITableView. If I click on UITableViewCell, how do I get all dates of that same day from NSMutableArray ?

So lets say I have 3 dates inserted on monday, 1 on tuesday, 4 on wednesday and so on... If I press 1/3 dates that represent monday, how can I get all 3 dates that are monday and ignore other days??

And if possible, how can I sort them ?? So If I saved in 8, 9, 10 hours (all on monday) and I press any of hours (minutes are also included), they will be sorted 8-9-10 exactly how they really happened...

Tnx.

Upvotes: 1

Views: 461

Answers (1)

aLevelOfIndirection
aLevelOfIndirection

Reputation: 3522

Date computation with NSDate and company is a bit complicated but actually quite powerful once you get the hang of it. Here is one way to filter your array:

int main (int argc, const char * argv[])
{
    @autoreleasepool {

        NSCalendar  *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
        NSMutableArray *dates = [NSMutableArray array];
        NSDate  *selectedDate = [NSDate date];

        for (int i=0;   i<70;  i++)
            [dates addObject:[NSDate dateWithTimeIntervalSinceNow:i * 60*60*24]];



        NSInteger selectedDayOfWeek = [calendar components:NSWeekdayCalendarUnit fromDate:selectedDate].weekday;

        NSPredicate *filter = [NSPredicate predicateWithBlock:^(id object, NSDictionary *bindings) {
            return (BOOL)([calendar components:NSWeekdayCalendarUnit fromDate:object].weekday == selectedDayOfWeek);
        }];

        NSArray *filteredDates = [dates filteredArrayUsingPredicate:filter];

        NSArray *sortedDates = [filteredArray sortedArrayUsingSelector:@selector(compare:)];

        NSLog(@"%@", filteredDates);
    }
    return 0;
}

Upvotes: 1

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