NSDate and NSString cocoa

For my iPhone app I got to开发者_StackOverflow convert NSDate object to string, and then convert the string back to NSDate object.. Can someone help me out? thank you!

Use to convert from NSDate to NSString

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy-MM-dd hh:mm:ss a"];
NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];

Use to convert from NSString to NSDate.

NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:@"yyyy-MM-dd hh:mm:ss a"];
NSDate *myDate = [df dateFromString: stringFromDate];

You need to check out NSDateFormatter this does exactly this, both directions.

convert NSDate to NSString

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy"];

//Optionally for time zone converstions

[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"..."]];

NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];

Convert NSString to NSDate

NSString *dateString = @"01-02-2010";

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

// this is imporant - we set our input date format to match our input string
// if format doesn't match you'll get nil from your string, so be careful

[dateFormatter setDateFormat:@"dd-MM-yyyy"];

NSDate *dateFromString = [[NSDate alloc] init];

// voila!
dateFromString = [dateFormatter dateFromString:dateString];

[dateFormatter release];