how to compare two NSString which have date - iphone

Question

I have two NSString which have date i want that if they both have same data then if should work otherwise else should work
here is my code
NSString*test=data.addedDateTime;
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"yyyy_MM_dd"];
NSDate* date = [NSDate date];
NSString* str = [formatter stringFromDate:date];
NSString*addedDateTime=str;
if ([test isEqualToString:str]) {
[todayArray addObject:theObject];
int count=[todayArray count];
NSLog(#"Today array working %d",count);
}
else {
[yesterdayArray addObject:theObject];
}
my code always runs else when there is same value in both i have checked using NSLog

Answer 1

Don't compare two NSStrings, which represent the dates, but compare two NSDates instead

Answer 2

First you convert string to date and use this [date1 isEqualToDate:date2].This is a compair a two date.
use this code I hope this code useful for you.
NSString*test=data.addedDateTime;
NSDateFormatter* df = [[NSDateFormatter alloc] init];
[df setDateFormat:#"yyyy_MM_dd"];
NSDate* d = [df dateFromString:test];
[df release];
NSDate* date = [NSDate date];
if ([d isEqualToDate:date) {
[todayArray addObject:theObject];
int count=[todayArray count];
NSLog(#"Today array working %d",count);
}
else {
[yesterdayArray addObject:theObject];
}

Answer 3

NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatter setDateFormat:#"yyyy-MM-dd"];
NSDate *date1 = [dateFormatter dateFromString:TodatDate];
NSDateFormatter *dateFormatte = [[[NSDateFormatter alloc] init] autorelease];
[dateFormatte setDateFormat:#"yyyy-MM-dd"];
NSDate *date2 = [dateFormatte dateFromString:ServerDate];
unsigned int unitFlags = NSDayCalendarUnit;
NSCalendar *gregorian = [[NSCalendar alloc]initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comps = [gregorian components:unitFlags fromDate:date1 toDate:date2 options:0];
int days = [comps day];
NSLog(#"%d",days);

Answer 4

Condition [test isEqualToString:str] always gives NO if date is either not equal or in not same formate. So dont use this.
Use NSDateComponent to compare two dates or Compare as #Andrey Gordeev
Says .

Answer 5

Try this code for any comparison between dates... You should not compare date in the form of string. Compare the dates before conversion to string. Convert the string "test" into date format using dateFromString function of the formatter by specifying the exact date format as that of the test. Then compare the dates using following function.
NSString*test=data.addedDateTime;
NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
[formatter setDateFormat:#"yyyy_MM_dd"];
NSDate *newDate = [formatter dateFromString:data.addedDateTime]; // other date
NSDate *today = [NSDate date]; // current date
NSComparisonResult result;
result = [today compare:newDate]; // comparing two dates
if(result == NSOrderedSame)
{
[todayArray addObject:theObject];
int count=[todayArray count];
NSLog(#"Today array working %d",count);
}
else
{
[yesterdayArray addObject:theObject];
}

Answer 6

Instead of comparing String compare Date. Like this,
NSDate *myDate1 =data.addedDateTime;
NSDate* mydate2 = [NSDate date];
if ([myDate1 compare:mydate2] == NSOrderedDescending) {
NSLog(#"Dilip myDate1 is later than myDate2");
} else if ([myDate1 compare:mydate2] == NSOrderedAscending) {
NSLog(#"Dilip myDate1 is earlier than myDate2");
} else {
NSLog(#"Dilip dates are the same");
}

Answer 7

first u should convert date to nsstring..
then u set perfect date formate in both string..
like
NSDate *today1 = [NSDate date];
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"dd-MM-yyyy"];
NSString *dateString11 = [dateFormat stringFromDate:today1];
[dateString11 retain];
ur first string is like dateString11
and other date string is like str2=#"03-10-2010";
then u compare two string
if ([dateString11 isEqualToString:str2]) {
[todayArray addObject:theObject];
int count=[todayArray count];
NSLog(#"Today array working %d",count);
}