CODEWITHSUNDEEP
cocoa
user1295948
user1295948

Reputation: 303

cocoa: how can i convert nsdate to nstimeinterval in cocoa?

 NSDate *newDate=[newDate dateByAddingTimeInterval:difference];

Now I want to convert this newDate to NStimeInterval.

How can I do this conversion?

Upvotes: 2

Views: 15827

Answers (3)

Dark
Dark

Reputation: 894

Just a bit shorter:

NSDate *date = ...

NSTimeInterval interval = [date timeIntervalSinceReferenceDate];

And to get it back:

date = [[NSDate alloc] initWithTimeIntervalSinceReferenceDate:timeInterval];

Upvotes: -1

Bruno Ferreira
Bruno Ferreira

Reputation: 952

NDDate and NSTimeInterval are two diferent things, you cannot convert a NSDate to a NSTimeInterval and vice-versa.

NSDate represents an absolute date and NSTimeInterval represents the time between two dates.

However you can create a NSTimeInterval from a reference date with this method:

- (NSTimeInterval)timeIntervalSinceDate:(NSDate *)anotherDate

You can do it like this:

NSDate *referenceDate = /* Your reference date */
NSDate *date = /* Your date */
NSTimeInterval timeInterval = [date timeIntervalSinceDate:referenceDate];

Upvotes: 13

trojanfoe
trojanfoe

Reputation: 122391

As I have mentioned in the comments above, you need to know what you want the NSTimeInterval to represent as it's the distance between two points in time (i.e. two NSDate instances).

If you want it to represent the time between your newDate and 01-Jan-2001 GMT you can use:

- (NSTimeInterval)timeIntervalSinceReferenceDate;

(reference).

However if you want it to represent the time since another reference date, you need to create that reference date as an NSDate object and use: 

- (NSTimeInterval)timeIntervalSinceDate:(NSDate *)anotherDate;

(reference).

Upvotes: 2

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