How to check if NSDate is in current week?

问题

How to check if NSDate falls in current week of the year? I tried below but last week's date is also falling inside "Date is in this week" condition.

- (NSInteger)thisW:(NSDate *)date
{
    NSCalendar *gregorian = [[NSCalendar alloc]
                             initWithCalendarIdentifier:NSGregorianCalendar];

    NSDateComponents *todaysComponents =
    [gregorian components:NSWeekCalendarUnit fromDate:[NSDate date]];

    NSUInteger todaysWeek = [todaysComponents weekday];


    NSDateComponents *otherComponents =
    [gregorian components:NSWeekCalendarUnit fromDate:date];

    NSUInteger datesWeek = [otherComponents weekday];
    NSLog(@"Date %@",date);
    if(todaysWeek==datesWeek){
        //NSLog(@"Date is in this week");
        return 1;
    }else if(todaysWeek+1==datesWeek){
        //NSLog(@"Date is in next week");
        return 2;
    } else {
        return 0;
    }

}

回答1:

What about this short extension in Swift 4?

extension Calendar {
    func isDayInCurrentWeek(date: Date) -> Bool? {
        let currentComponents = Calendar.current.dateComponents([.weekOfYear], from: Date())
        let dateComponents = Calendar.current.dateComponents([.weekOfYear], from: date)
        guard let currentWeekOfYear = currentComponents.weekOfYear, let dateWeekOfYear = dateComponents.weekOfYear else { return nil }
        return currentWeekOfYear == dateWeekOfYear
    }
}

回答2:

I had to replace NSWeekCalendarUnit with NSCalendarUnitWeekOfYear

- (NSInteger)thisW:(NSDate *)date
{
    NSCalendar *gregorian = [[NSCalendar alloc]
                             initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents *todaysComponents = [gregorian components:NSCalendarUnitWeekOfYear fromDate:[NSDate date]];
    NSUInteger todaysWeek = [todaysComponents weekOfYear];
    NSDateComponents *otherComponents = [gregorian components:NSCalendarUnitWeekOfYear fromDate:date];
    NSUInteger datesWeek = [otherComponents weekOfYear];

    //NSLog(@"Date %@",date);
    if(todaysWeek==datesWeek){
        //NSLog(@"Date is in this week");
        return 1;
    }else if(todaysWeek+1==datesWeek){
        //NSLog(@"Date is in next week");
        return 2;
    } else {
        return 0;
    }

}

回答3:

A solution using the method rangeOfUnit:startDate:interval:forDate of NSCalendar to calculate the start date and the interval of the current week

- (BOOL)isInCurrentWeek:(NSDate *)date
{
  NSDate *startDate = nil;
  NSTimeInterval interval = 0.0;
  NSCalendar *calendar = [NSCalendar currentCalendar];
  // calendar.firstWeekday = 1; set the index of the first weekday if necessary
  [calendar rangeOfUnit:NSWeekOfYearCalendarUnit startDate: &startDate interval: &interval forDate: [NSDate date]];
  NSDate *endDate = [calendar dateByAddingUnit:NSSecondCalendarUnit value: (NSInteger)interval toDate: startDate options:NSCalendarMatchNextTime];
  return [date compare:startDate] == NSOrderedDescending && [date compare:endDate] == NSOrderedAscending;
}

or in Swift

func isDateInCurrentWeek(_ date : Date) -> Bool
{
    var startDate = Date()
    var interval : TimeInterval = 0.0
    let calendar = Calendar.current
    // calendar.firstWeekday = 1 set the index of the first weekday if necessary
    calendar.dateInterval(of: .weekOfYear, start: &startDate, interval: &interval, for: Date())
    let endDate = calendar.date(byAdding:.second, value: Int(interval), to: startDate)!
    return date >= startDate && date < endDate
}

回答4:

Use this function to get number of week:

- (NSInteger)numberOfWeek:(NSDate *)date
{
    NSCalendar *calender = [NSCalendar currentCalendar];
    NSDateComponents *components = [calender components:NSCalendarUnitWeekOfYear fromDate:date];
    return [components weekOfYear];
}

Using this code, you can compare week like this. I am just use next week date using dateWithTimeIntervalSinceNow: only for comparison.

if ([self numberOfWeek:[NSDate date]] == [self numberOfWeek:[NSDate dateWithTimeIntervalSinceNow: (60.0f*60.0f*24.0f*7.0f)]])
{
    NSLog(@"Same Week");
}
else
{
    NSLog(@"Different Week");
}

回答5:

First get the firstday and lastday of the week of current date.

NSCalendar *myCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

NSDateComponents *currentComps = [myCalendar components:( NSYearCalendarUnit | NSMonthCalendarUnit | NSWeekOfYearCalendarUnit | NSWeekdayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit) fromDate:[NSDate date]];


[currentComps setWeekday:1]; // 1: sunday
NSDate *firstDayOfTheWeek = [myCalendar dateFromComponents:currentComps];
[currentComps setWeekday:7]; // 7: saturday
NSDate *lastDayOfTheWeek = [myCalendar dateFromComponents:currentComps];

Now use a method given bellow putting your interested date

BOOL isInCurrentWeek = [self date:your given date isBetweenDate:firstDayOfTheWeek andDate:lastDayOfTheWeek];
NSLog(@"%d",isInCurrentWeek);

The expecting method

- (BOOL)date:(NSDate*)date isBetweenDate:(NSDate*)beginDate andDate:(NSDate*)endDate
{
    if ([date compare:beginDate] == NSOrderedAscending)
        return NO;

    if ([date compare:endDate] == NSOrderedDescending)
        return NO;

    return YES;
}

来源：https://stackoverflow.com/questions/38970836/how-to-check-if-nsdate-is-in-current-week

标签

ios

objective-c

nsdate