how to use nsdate string objec for later use?

Question

I'm so fedup with NSDate string object. currently I am generating an unique id on the bases of NSDate as follows:

NSDate *current_date = [[NSDate date]retain];
NSDateFormatter *df = [[NSDateFormatter alloc]init];
[df setDateFormat:@"HHmmssddMMYY"];
NSString *unique_id=[df stringFromDate:current_date];
NSString  *   current_Test_id=[NSString stringWithString:unique_id];
NSLog(@"current_test_idString %@",current_Test_id);

The code above is generating unique id and prints successfully but if I am printing or accessing currtent_Test_id in another IBAction method then app crashes.

is current_Test_id an ivar and are you releasing current_date anywhere? — Anoop Vaidya, Dec 31 '12 at 12:05
@AnoopVaidya: its nsstring. and i'm not releasing current_date anyware? — Bhoopi, Dec 31 '12 at 12:08
if current_test_id is global, so plz tell me is it instance variable of your class ? — Anoop Vaidya, Dec 31 '12 at 12:11

junaidsidhu · Answer 1 · 2012-12-31T12:19:18.247

1

Use this Method

 - (NSString *)stringDateFromDate: (NSDate *) date{

    NSDateFormatter *df = [[NSDateFormatter alloc]init];
    [df setDateFormat:@"HHmmssddMMYY"]; 
    NSString *current_Test_id=[NSString stringWithString:[df stringFromDate:date]];
    [df release];
    NSLog(@"current_tst_id %@",current_Test_id);

    return current_Test_id;

}

Call Method Like that

NSString  *current_tst_id = [self stringDateFromDate:[NSDate date]];

edited Dec 31 '12 at 12:19

answered Dec 31 '12 at 12:13

junaidsidhu

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please check it in instrument, I dont think that there is memory leak – junaidsidhu Dec 31 '12 at 12:23
Now its fine, your initial answer did not contain `[df release]`. You corrected it 8 mins ago... :) – Anoop Vaidya Dec 31 '12 at 12:27
if it was missing then you must have to edit it and change the code, as you can. – junaidsidhu Dec 31 '12 at 12:29
yes thats why, i gave you time to check and correct. I did not use my downvote. However Good Work. But his problem was something else, he wanted to set the id to ivar...and he missed to retain it. – Anoop Vaidya Dec 31 '12 at 12:30

score 1 · Accepted Answer · answered Dec 31 '12 at 12:14

1

stringWithString will create an autorelease string, modify your code as

NSString  *   current_Test_id = [[NSString stringWithString:unique_id]retain];

answered Dec 31 '12 at 12:14

ask4asif

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score 0 · Answer 3 · edited May 23 '17 at 12:27

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an NSString (or any object, for that matter) created with a class method, and not an init method, will be autoreleased. This means on the next iteration of the event loop, current_Test_id is released, and now you have a pointer to a dead object.

See this similar question

edited May 23 '17 at 12:27

Community

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answered Dec 31 '12 at 12:12

Phil Frost

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Anoop Vaidya · Answer 4 · 2012-12-31T12:25:37.523

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As current_Test_id is instance method.

in the init (in case of mac os) or viewDidLoad (for ios) alloc+init it.

and then assign :

current_Test_id=[NSString stringWithString:unique_id]; //it will be in autorelease mode.

or

current_Test_id=[[NSString stringWithString:unique_id]retain];

edited Dec 31 '12 at 12:25

answered Dec 31 '12 at 12:14

Anoop Vaidya

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how to use nsdate string objec for later use?

4 Answers4