Compare dates using cocoa objective c

Question

Is it necessary that i have to write the following method to call it in the if....part.

-(NSComparisonResult) compare:(NSDate *)expDate{}

if yes, then how and where i have to write this method so that the following code will work fine?

if (licenseDictionary == nil)
    return @"Not Registered";
else if([today compare:expDate] == NSOrderedAscending)
{   
    [gotoButton setEnabled:YES];
    return [licenseDictionary objectForKey:@"Name"];
}
else
    return @"License Expired";

Answer 1

There are also earlierDate: and laterDate: and isEqualToDate:.

You can find the documentation on them here.

So something like:

if ([today laterDate:expDate] == expDate)

That's dry-coded here in the browser, but I think that's what you'd want.

EDIT: I fixed a typo in the above, you don't need to use compare:. laterDate: and earlierDate: handle the comparisons and return the object that is later or earlier respectively.

So the above code says which one is later, today or expDate, and if expDate is the later one (pointer comparison should work here I think, but if not try isEqualToDate: instead) then it hasn't expired yet and their license should be valid.

I hope that helps make more sense.