Why it cause an "exc_bad_access" error?

a simple test--

- (void)viewDidLoad
{
[super viewDidLoad]开发者_开发问答;

NSDate *date1 = [NSDate date];
NSDate *date2 = [NSDate dateWithTimeIntervalSinceNow:3];

NSTimeInterval timeBetween = [date1 timeIntervalSinceDate:date2];
NSLog(@"between: %@",timeBetween);    

}

It got an error in line "NSTimeInterval..."

program received signal: 'EXC_BAD_ACCESS'

Would you tell me where is wrong?

---

you're using a string format code instead of a number format code in your NSLog statement. try:

NSLog(@"between: %f",timeBetween);