如何在iPhone中比较两个日期？

Question

I want to compare the todays date and other date coming from my database. For example, 2011-03-25 compare it with 2011-02-25

How can i formate my database date as the NSDateFormatter require NSDdate datatype ?

Answer 1

Cocoa has couple of methods for this:

in NSDate

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

When you use - (NSComparisonResult)compare:(NSDate *)anotherDate ,you get back one of these:

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.

for more read the SO post

Just go through the blog post, there are many date related utility functions.

http://arstechnica.com/apple/guides/2010/03/how-to-real-world-dates-with-the-iphone-sdk.ars/2

Answer 2

NSDate *date1 = [NSDate date];
NSDate *date2 = [NSDate date];

if ([date1 compare: date2]==NSOrderedAscending) {
    NSLog(@"YES");
}

Answer 3

In Swift :

let date1 = NSDate() //some date
let date2 = NSDate() //another date

let firstDate = date1.earlierDate(date2)
let lastDate = date1.laterDate(date2)

Answer 4

http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/DatesAndTimes/Articles/dtDates.html#//apple_ref/doc/uid/20000183-BCIDBADB

Isn't that the same on Iphone?

Answer 5

If your date are string like year-month-day, you can just compare string:

 if ([date1 compare:string2]==NSOrderedAscending) {
 } else if ([date1 compare:string2]== NSOrderedDescending) {
 } else {
 }

It will works because fields in date are from most important to less, like a string comparison.

Answer 6

您可以使用NSDate compare：或timeIntervalSinceReferenceDate-这将使您入门