Objective-C timespan

Question

In C#, if I wanted to parse out a string into a date and timespan, I'd do something similar to the following:

String input = "08:00";
DateTime time;
if (!DateTime.TryParse(input, out time))
{
    // invalid input
    return;
}

TimeSpan timeSpan = new TimeSpan(time.Hour, time.Minute, time.Second);

My Google-Fu has been less than desirable in finding a way to convert this to Objective-C.

Any suggestions?

Answer 1

The Date and Time Programming Guide for Cocoa will likely be helpful for finding an approach that best fits your needs. I'd bet that NSDateComponents will be of particular interest — you can obtain an instance of this class from the -[NSCalendar components:fromDate:] method.

As far as getting the date from a string, one approach you could try is using NSDateFormatter, which has methods like -dateFromString: and -stringFromDate: to convert between NSString and NSDate representations. You can use -setDateFormat: to specify the format string to use for parsing. Once you have an NSDate object, you can also use one of its -timeIntervalSince... methods to get an NSTimeInterval which is a double value, measured in seconds.