NSDateFormatter does return what is expected

I created a method to return the NSDate from a NSString. Code is below. I send to the function "2/25/2011". The functi开发者_如何学Goon returns "2010-12-26 08:00:00 +0000"

What did I do wrong? Also the NSString I need to release at the end. How do I do that?

thank you!

-(NSDate *) GetDatefromString:(NSString *) Str
{

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];

    [formatter setDateFormat:@"MM-dd-YYYY"];

    NSDate *dateFromString;
            // = [[NSDate alloc] init]; tried taking this part out but still not working


    if (Str != NULL)
    {
        dateFromString = [formatter dateFromString:Str];

    }
    else
    {
        dateFromString = [formatter dateFromString:@"1/1/1970"];
    }

    [formatter release];

     return dateFromString;    

// how do I release dateFromString?

  /*  
    Printing description of dateFromString:
    2010-12-26 08:00:00 +0000
    Printing description of Str:
    02-25-2011
  */  
}

You are passing in a date using the / seperator but you specified - as a separator for your date formatter. As to your question on releasing the string, you should only release objects that you own, i.e. that you have created with new, alloc, copy, or mutableCopy. See examples below.

NSDateFormatter* formatter = [[NSDateFormatter alloc] init]; // needs releasing
[formatter setDateFormat:@"MM-dd-yyyy"];

NSString* str1 = @"06/25/2011"; // does not need releasing
NSString* str2 = [[NSString alloc] initWithString:@"06-25-2011"]; // needs releasing

NSDate* date1 =  [formatter dateFromString:str1]; // does not need releasing
NSDate* date2 =  [[NSDate alloc] init]; // needs releasing
date2 = [formatter dateFromString:str2]; 

NSLog(@"date from %@ : %@", str1, date1);
NSLog(@"date from %@ : %@", str2, date2);

// release the objects you own
[formatter release];
[str2 release];
[date2 release];

// prints out
date from 06/25/2011 : (null)
date from 06-25-2011 : 2011-06-25 00:00:00 -0700

you set the format to@"MM-dd-YYYY"but the string you pass in has the form @"1/1/1970". That doesn't match. see Data Formatting Guide: Date formatters.

// how do I release dateFromString?

With autorelease.

return [dateFromString autorelease];

See Memory management.

The problem I had was the format had CAP LETTERS for the YEAR.

This is correct:

 [formatter setDateFormat:@"MM/dd/yyyy"];

And this is wrong: NOTE THE CAPS YYYY

[formatter
setDateFormat:@"MM-dd-YYYY"];