CODEWITHSUNDEEP
iosnsdatensdateformatter
samir
samir

Reputation: 4551

NSDate from NSDateFormatter

I am testing some dateFormatter and i have a problem with a simple 

formatter :

- (void)testDate {

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    [dateFormatter setDateFormat:@"dd/MM/yyyy"];
    NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"fr_FR"];
    [dateFormatter setLocale:locale];
    NSString *stringDate = @"23/03/1";
    NSDate *date = [dateFormatter dateFromString:stringDate];
    XCTAssertTrue(date == nil);
}

My tests is red because the date is not nil. When i print the date :

(lldb) po date
0001-03-22 23:50:39 +0000

The NSDateFormatter is padding the date string ( 1 ----> 0001).I don't want this padding. Do you think that it's the correct behaviour of the NSDateFormatter ? ( is it a bug in the NSDateFormatter class ? ). How i can avoid this ?

Thanks

Upvotes: 1

Views: 107

Answers (3)

Rob
Rob

Reputation: 437381

I don't think there's a good answer to why is @"23/03/1" considered a valid date with a formatter of @"dd/MM/yyyy". That's just how it works. But if you want to test to see if it's in ##/##/#### format, you could do:

NSRange range = [stringDate rangeOfString:@"^\\d{2}/\\d{2}/\\d{4}$" options:NSRegularExpressionSearch];
XCTAssert(range.location == NSNotFound, @"Not in ##/##/#### format");

Clearly, you'll have to combine that with the NSDateFormatter test to make sure that the values are reasonable, too, but the above will test the number of digits.

Upvotes: 1

Polina
Polina

Reputation: 273

My guess is that as "dd/MM/yyyy" is just a format, when NSDateFormatter processes it, parses given date as 3 numbers and makes transition to date. So "1" is just transferred to "0001".

Upvotes: 0

zaph
zaph

Reputation: 112857

The date formatter is only being used for parsing the string date to an NSDate.

The lldb po command just formats the date based on what some Apple developer thought would be good and it just for debugging. Internally NSDate uses a proprietary format we believe to be the number of seconds since the first instant of 1 January 2001, GMT.

What you want is to use the date formatter to format the date into the string format you want.

Example code using the format string in the question code:

NSString *dateString = [dateFormatter stringFromDate:date];
NSLog(@"dateString: %@", dateString);

Output:

dateString: 23/03/1999

Add an output date format to meet your needs.

Upvotes: 0

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