Converting a string to an NSDate

How is it possible to convert a string to an NSDate on iOS?

NSString *dateStr = @"20100223";
 
// Convert string to date object
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"yyyyMMdd"];
NSDate *date = [dateFormat dateFromString:dateStr];  
 
// Convert date object to desired output format
[dateFormat setDateFormat:@"EEEE MMMM d, YYYY"];
dateStr = [dateFormat stringFromDate:date];  
[dateFormat release];

Hope this will help you.

You'll want to take a look at NSDateFormatter. Determine the format of the date string and then use dateFromString: to convert the string to an NSDate object.

NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:@"dd/MM/YYYY"];
NSDate *date = [dateFormat dateFromString:dateStr];  
list = [self getYear:date];


- (NSMutableArray *)getYear:(NSDate*)date
{
    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:date];

    int year = [components year];
    int month = [components month];
    int day = [components day];
    NSLog(@"%d",year);

    NSMutableDictionary *dateDict = [[NSMutableDictionary alloc] initWithObjectsAndKeys:[NSString stringWithFormat:@"%d", day], @"day", [NSString stringWithFormat:@"%d", month], @"month", [NSString stringWithFormat:@"%d", year], @"year", nil];
    
    return dateDict;
}

My working version in Swift

func dateFor(timeStamp: String) -> NSDate
{
    let formater = NSDateFormatter()
    formater.dateFormat = "HH:mm:ss:SSS - MMM dd, yyyy"
    return formater.dateFromString(timeStamp)!
}


func timeStampFor(date: NSDate) -> String
{
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "HH:mm:ss:SSS - MMM dd, yyyy"
    
    return dateFormatter.stringFromDate(date)
}

A simple approach even if you have sqlite DB:

// NSTimeInterval is basically typedef of double so you can receive it as double also.
NSTimeInterval *current = [[NSDate date] timeIntervalSince1970]; 
[DB addToDB:current];

//retrieve the date from DB
NSDate *retrievedDateItem = [[NSDate alloc] initWithTimeIntervalSince1970:[getDBValueAsDouble]]; //convert it from double (NSTimeInterval) to NSDate
// Set the style
[dateFormatter setDateStyle:NSDateFormatterMediumStyle];
[dateFormatter setTimeStyle:NSDateFormatterMediumStyle];
// Converted to string
NSString *convertedDate = [dateFormatter stringFromDate:retrievedDateItem];

The output for this example:

Aug 3, 2015, 12:27:50 PM

+(NSDate*)str2date:(NSString*)dateStr{
    if ([dateStr isKindOfClass:[NSDate class]]) {
        return (NSDate*)dateStr;
    }
    
    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"yyyy-MM-dd"];
    NSDate *date = [dateFormat dateFromString:dateStr];
    return date;
}