MKReverseGeocoder placemark is empty

I am trying to get the placemark for a location but all I am getting is empty. Here is my header file.

#import <Foundation/Foundation.h>
#import <MapKit/MapKit.h>


@interface ReverseGeoCodingHelper : NSObject<MKReverseGeocoderDelegate> {
    MKReverseGeocoder *reverseGeocoder;
    MKPlacemark *dootPlacemark;
}

@property (nonatomic, retain) MKReverseGeocoder *reverseGeocoder;
@property (nonatomic, retain) MKPlacemark *dootPlacemark;

- (vo开发者_JS百科id)reverseGeocode;

@end

and here is my .m file

#import "ReverseGeoCodingHelper.h"

@implementation ReverseGeoCodingHelper
@synthesize reverseGeocoder,dootPlacemark;


- (void)reverseGeocode
{

    if (self.reverseGeocoder != nil)
    {
        // release the existing reverse geocoder to stop it running
        [self.reverseGeocoder release];
    }

    CLLocationCoordinate2D locationToLookup = {37.40091, -122.01635};

    self.reverseGeocoder =
    [[MKReverseGeocoder alloc]initWithCoordinate:locationToLookup];

    reverseGeocoder.delegate = self;
    [reverseGeocoder start];
}

// MKReverseGeocoderDelegate methods
/**
 Gets called when MKReverseGeocoder finds info for your coordinate, 
 you can retrieve info you need from corresponding fields of MKPlacemark instance you    
get
*/
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder  didFindPlacemark:(MKPlacemark  
*)placemark{

    NSString* city = [placemark.addressDictionary valueForKey:@"City"];
    NSString* street = [placemark.addressDictionary valueForKey:@"Street"]; 
    NSLog(@"Placemark is : @, @, @, @", [placemark country], [placemark locality], 
 city, street);
}
- (void)reverseGeocoder:(MKReverseGeocoder *)geocoder didFailWithError:(NSError *)error{
    NSString *errorMessage = [error localizedDescription];
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"Cannot obtain   
        address." message:errorMessage
                                                delegate:nil
                                          cancelButtonTitle:@"OK"
                                          otherButtonTitles:nil];
[alertView show];
[alertView release];
}

- (void)dealloc{
[reverseGeocoder release];
[super dealloc];
}

@end

didFindPlacemark method is getting called but NSLog is not printing any values for any of the attribute they all the empty.

In the NSLog, placeholders for the string variables should be %@ (not just @):

NSLog(@"Placemark is : %@, %@, %@, %@", [placemark country], 
    [placemark locality], city, street);