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Objective-Cで2つの日付を比較する方法

2つの日付があります：2009-05-11および現在の日付。指定した日付が現在の日付かどうかを確認したい。これはどのように可能ですか。

objective-ccocoadatedate-comparison
66
Raju

ココアにはこのためのメソッドがいくつかあります ：

nSDate

_– isEqualToDate:  
– earlierDate:  
– laterDate:  
– compare:
_

- (NSComparisonResult)compare:(NSDate *)anotherDateを使用すると、次のいずれかが返されます。

_The receiver and anotherDate are exactly equal to each other, NSOrderedSame
The receiver is later in time than anotherDate, NSOrderedDescending
The receiver is earlier in time than anotherDate, NSOrderedAscending.
_

例：

_NSDate * now = [NSDate date];
NSDate * mile = [[NSDate alloc] initWithString:@"2001-03-24 10:45:32 +0600"];
NSComparisonResult result = [now compare:mile];

NSLog(@"%@", now);
NSLog(@"%@", mile);

switch (result)
{
    case NSOrderedAscending: NSLog(@"%@ is in future from %@", mile, now); break;
    case NSOrderedDescending: NSLog(@"%@ is in past from %@", mile, now); break;
    case NSOrderedSame: NSLog(@"%@ is the same as %@", mile, now); break;
    default: NSLog(@"erorr dates %@, %@", mile, now); break;
}

[mile release];
_
156
stefanB

ここでバディ。この関数は、日付を特定の日付と一致させ、一致するかどうかを判断できます。要件に合わせてコンポーネントを変更することもできます。

- (BOOL)isSameDay:(NSDate*)date1 otherDay:(NSDate*)date2 {
NSCalendar* calendar = [NSCalendar currentCalendar];

unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit;
NSDateComponents* comp1 = [calendar components:unitFlags fromDate:date1];
NSDateComponents* comp2 = [calendar components:unitFlags fromDate:date2];

return [comp1 day]   == [comp2 day] &&
[comp1 month] == [comp2 month] &&
[comp1 year]  == [comp2 year];}

よろしく、Naveed Butt

44
Naveed Rafi
NSDate *today = [NSDate date]; // it will give you current date
NSDate *newDate = [NSDate dateWithString:@"xxxxxx"]; // your date 

NSComparisonResult result; 
//has three possible values: NSOrderedSame,NSOrderedDescending, NSOrderedAscending

result = [today compare:newDate]; // comparing two dates

if(result==NSOrderedAscending)
    NSLog(@"today is less");
else if(result==NSOrderedDescending)
    NSLog(@"newDate is less");
else
    NSLog(@"Both dates are same");

NSDateオブジェクトを比較するために使用できる他の方法があります。各メソッドは、特定のタスクでより効率的になります。基本的な日付比較のニーズのほとんどを処理するため、比較方法を選択しました。

40
Sajjad

これ カテゴリはNSDatesを比較するためのきちんとした方法を提供します：

#import <Foundation/Foundation.h>

@interface NSDate (Compare)

-(BOOL) isLaterThanOrEqualTo:(NSDate*)date;
-(BOOL) isEarlierThanOrEqualTo:(NSDate*)date;
-(BOOL) isLaterThan:(NSDate*)date;
-(BOOL) isEarlierThan:(NSDate*)date;
//- (BOOL)isEqualToDate:(NSDate *)date; already part of the NSDate API

@end

そして実装：

#import "NSDate+Compare.h"

@implementation NSDate (Compare)

-(BOOL) isLaterThanOrEqualTo:(NSDate*)date {
    return !([self compare:date] == NSOrderedAscending);
}

-(BOOL) isEarlierThanOrEqualTo:(NSDate*)date {
    return !([self compare:date] == NSOrderedDescending);
}
-(BOOL) isLaterThan:(NSDate*)date {
    return ([self compare:date] == NSOrderedDescending);

}
-(BOOL) isEarlierThan:(NSDate*)date {
    return ([self compare:date] == NSOrderedAscending);
}

@end

使いやすい：

if([aDateYouWantToCompare isEarlierThanOrEqualTo:[NSDate date]]) // [NSDate date] is now
{
    // do your thing ...
}
31
Pascal

両方の日付をNSDatesにすると、NSDateのcompare: 方法：

NSComparisonResult result = [Date2 compare:Date1];

if(result==NSOrderedAscending)
    NSLog(@"Date1 is in the future");
else if(result==NSOrderedDescending)
    NSLog(@"Date1 is in the past");
else
    NSLog(@"Both dates are the same");

Docs here をご覧ください。

21
Alex Rozanski

この方法では、2つの日付を比較することもできます

NSDate * dateOne = [NSDate date];
NSDate * dateTwo = [NSDate date];

if([dateOne compare:dateTwo] == NSOrderedAscending)
{

}
15
kapil

私が見つけた最良の方法は、指定された日付と今日の違いを確認することでした：

NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* now = [NSDate date];
int differenceInDays =
[calendar ordinalityOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitEra forDate:date] -
[calendar ordinalityOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitEra forDate:now];

Appleの 日付と時刻プログラミングガイド の Calendrical Calculations のリスト13によると、[NSCalendar ordinalityOfUnit：NSDayCalendarUnit inUnit：NSEraCalendarUnit forDate：myDate]は、開始からの真夜中の数を示します時代。これにより、日付が昨日か、今日か、明日かを簡単に確認できます。

switch (differenceInDays) {
    case -1:
        dayString = @"Yesterday";
        break;
    case 0:
        dayString = @"Today";
        break;
    case 1:
        dayString = @"Tomorrow";
        break;
    default: {
        NSDateFormatter* dayFormatter = [[NSDateFormatter alloc] init];
        [dayFormatter setLocale:usLocale];
        [dayFormatter setDateFormat:@"dd MMM"];
        dayString = [dayFormatter stringFromDate: date];
        break;
    }
}
8
Chei
NSDateFormatter *df= [[NSDateFormatter alloc] init];

[df setDateFormat:@"yyyy-MM-dd"];

NSDate *dt1 = [[NSDate alloc] init];

NSDate *dt2 = [[NSDate alloc] init];

dt1=[df dateFromString:@"2011-02-25"];

dt2=[df dateFromString:@"2011-03-25"];

NSComparisonResult result = [dt1 compare:dt2];

switch (result)
{

        case NSOrderedAscending: NSLog(@"%@ is greater than %@", dt2, dt1); break;

        case NSOrderedDescending: NSLog(@"%@ is less %@", dt2, dt1); break;

        case NSOrderedSame: NSLog(@"%@ is equal to %@", dt2, dt1); break;

        default: NSLog(@"erorr dates %@, %@", dt2, dt1); break;

}

コーディングをお楽しみください......

4
iphonedev23

Cocoaでは、日付を比較するには、isEqualToDateオブジェクトのcompare、laterDate、earlierDate、およびNSDateメソッドのいずれかを使用し、必要な日付。

ドキュメンテーション：
http://developer.Apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//Apple_ref/occ/instm/NSDate/isEqualToDate :
http://developer.Apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//Apple_ref/occ/instm/NSDate/earlierDate :
http://developer.Apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//Apple_ref/occ/instm/NSDate/laterDate :
http://developer.Apple.com/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//Apple_ref/occ/instm/NSDate/compare :

3
Suvesh Pratapa

本当に必要なのは、同じ種類の2つのオブジェクトを比較することです。

  1. 文字列の日付（@ "2009-05-11"）からNSDateを作成します。
    http://blog.evandavey.com/2008/12/how-to-convert-a-string-to-nsdate.html

  2. 現在の日付も文字列である場合は、NSDateにします。既にNSDateである場合は、そのままにします。

2
David Salzer

パスカルの答えのSwiftバリアント：

extension NSDate {

    func isLaterThanOrEqualTo(date:NSDate) -> Bool {
        return !(self.compare(date) == NSComparisonResult.OrderedAscending)
    }

    func isEarlierThanOrEqualTo(date:NSDate) -> Bool {
        return !(self.compare(date) == NSComparisonResult.OrderedDescending)
    }

    func isLaterThan(date:NSDate) -> Bool {
        return (self.compare(date) == NSComparisonResult.OrderedDescending)
    }

    func isEarlierThan(date:NSDate) -> Bool {
        return (self.compare(date) == NSComparisonResult.OrderedAscending)
    }
}

次のように使用できます：

self.expireDate.isEarlierThanOrEqualTo(NSDate())
1
Antoine

Naveed Rafi の答えをSwift誰かが探している場合に変換：

func isSameDate(#date1: NSDate, date2: NSDate) -> Bool {
    let calendar = NSCalendar()
    let date1comp = calendar.components(.YearCalendarUnit | .MonthCalendarUnit | .DayCalendarUnit, fromDate: date1)
    let date2comp = calendar.components(.YearCalendarUnit | .MonthCalendarUnit | .DayCalendarUnit, fromDate: date2)
    return (date1comp.year == date2comp.year) && (date1comp.month == date2comp.month) && (date1comp.day == date2comp.day)
}
1
spanndemic
Get Today's Date:

NSDate* date = [NSDate date];

Create a Date From Scratch:    
NSDateComponents* comps = [[NSDateComponents alloc]init];
comps.year = 2015;
comps.month = 12;
comps.day = 31;
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* date = [calendar dateFromComponents:comps];


Add a day to a Date:  
NSDate* date = [NSDate date];
NSDateComponents* comps = [[NSDateComponents alloc]init];
comps.day = 1;
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* tomorrow = [calendar dateByAddingComponents:comps toDate:date options:nil];


Subtract a day from a Date:    
NSDate* date = [NSDate date];
NSDateComponents* comps = [[NSDateComponents alloc]init];
comps.day = -1;
NSCalendar* calendar = [NSCalendar currentCalendar];
NSDate* yesterday = [calendar dateByAddingComponents:comps toDate:date options:nil];



Convert a Date to a String:  

NSDate* date = [NSDate date];
NSDateFormatter* formatter = [[NSDateFormatter alloc]init];
formatter.dateFormat = @"MMMM dd, yyyy";
NSString* dateString = [formatter stringFromDate:date];


Convert a String to a Date:

NSDateFormatter* formatter = [[NSDateFormatter alloc]init];
formatter.dateFormat = @"MMMM dd, yyyy";
NSDate* date = [formatter dateFromString:@"August 02, 2014"];


Find how many days are in a month:    
NSDate* date = [NSDate date];
NSCalendar* cal = [NSCalendar currentCalendar];
NSRange currentRange = [cal rangeOfUnit:NSDayCalendarUnit inUnit:NSMonthCalendarUnit forDate:date];
NSInteger numberOfDays = currentRange.length;


Calculate how much time something took:   

NSDate* start = [NSDate date];
for(int i = 0; i < 1000000000; i++);
NSDate* end = [NSDate date];
NSTimeInterval duration = [end timeIntervalSinceDate:start];


Find the Day Of Week for a specific Date:

NSDate* date = [NSDate date];
NSCalendar* cal = [NSCalendar currentCalendar];
NSInteger dow = [cal ordinalityOfUnit:NSWeekdayCalendarUnit inUnit:NSWeekCalendarUnit forDate:date];

次に、NSComparisonResultを使用して日付を比較します。

0
Avijit Nagare