NSDate与NSDateFormatter返回零日期

Question

I want to convert a string to an NSDate, like this:

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateStyle:NSDateFormatterFullStyle];
NSDate *createdAt = [dateFormat dateFromString:[value valueForKey:@"created_at"]];

When I log createdAt it returns nil for some reason and I can't figure out why.

[value valueForKey:@"created_at"]];
Returns a NSCFString that looks like this:
2013-05-15T05:55:57Z

I have no idea why it's nil, any help would be appreciated!

Answer 1

You should set date format to the NSDateFormatter first. This should be working:

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss'Z'"];
NSDate *createdAt = [dateFormat dateFromString:[value valueForKey:@"created_at"]];

However I'm not sure about your input date string. The last letter Z should be identification of date's time zone. Letter Z is the format specifier for the time zone according to Unicode Date Format Patterns ( http://www.unicode.org/reports/tr35/tr35-25.html#Date_Format_Patterns ).