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Getting Current Time in string in Custom format in objective c

Answer 1

+9 A:

You want a date formatter. Here's an example:

NSDateFormatter *formatter;
NSString        *dateString;

formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"dd-MM-yyyy HH:mm"];

dateString = [formatter stringFromDate:[NSDate date]];

[formatter release];  // maybe; you might want to keep the formatter 
                      // if you're doing this a lot.

Carl Norum 2009-11-06 01:53:08

Edited for iphone-ness.

Carl Norum 2009-11-06 02:21:00

<pedantic>don't forget to release your formatter.</pedantic>

Frank Schmitt 2009-11-06 03:45:30

Unless you want to keep it around; memory management may or may not enter into the problem.

Carl Norum 2009-11-06 06:09:28

Date formatters are really slow to set up. If you are setting dates in a table cell or doing it a lot, as was mentioned above, you'll want to retain it, us it for everything, then release it in dealloc.

Steve Weller 2009-11-07 06:08:22

Answer 2

+3 A:

Either use NSDateFormatter as Carl said, or just use good old strftime, which is also perfectly valid Objective-C:

#import <time.h>
time_t currentTime = time(NULL);
struct tm timeStruct;
localtime_r(&currentTime, &timeStruct);
char buffer[20];
strftime(buffer, 20, "%d-%m-%Y %H:%M", &timeStruct);

Stephen Canon 2009-11-06 03:29:44

Note that you can't do too much with a C string in Objective C. This might be more convenient when logging something to the console. You can just say `NSLog(@"%s", buffer)`.

Dustin Voss 2009-11-06 05:27:57

Anything you can do with a C string in C, you can do in Objective-C. Which is to say, pretty much everything. One should feel free to use both C strings and NSStrings, and pick the appropriate one for the current use case. I personally would go with Carl's solution, but it's important to be aware that it's not the only way.

Stephen Canon 2009-11-06 15:28:16

I would say the reason not to use strftime (despite it generating a C string that you then have to convert) is that you also lose out on the far greater flexibility of the NSDateFormatter date formatting options, including more variable length of numeric results and so on.

Kendall Helmstetter Gelner 2009-11-06 23:06:17

Did I really get a down vote for demonstrating a (perfectly valid) alternative solution?

Stephen Canon 2009-11-06 23:41:56

this should be the preferred way on iOS becayuse of this bug http://stackoverflow.com/questions/143075/nsdateformatter-am-i-doing-something-wrong-or-is-this-a-bug , however i am finding that time() or localtime_r() are not always accurate, am seeing very weird results.

valexa 2010-09-12 01:32:07

Answer 3

A:

1> If you are setting dates a lot,

2> you'll want to retain it, us it for everything,

3> then release it in dealloc

Can someone give a code example for #2?

Donna 2009-12-24 04:01:40

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Getting Current Time in string in Custom format in objective c

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