ivar behave in 2 different way, with same usage - ios

Question

i tried 2 different apps to test few things.
the first app its simple
ViewController.h
#import <UIKit/UIKit.h>
#interface ViewController : UIViewController {
NSMutableString *text;
}
#property (nonatomic, retain)NSMutableString *text;
#end
ViewController.m
#import "ViewController.h"
#interface ViewController ()
#end
#implementation ViewController
#synthesize text = text;
- (void)viewDidLoad
{
[super viewDidLoad];
text = #"FOO";
NSLog(#"%#", text);
self.text = #"FOO2";
NSLog(#"%#", self.text);
NSLog(#"1:%# - 2:%#", text, self.text);
}
this made things seems like synthesizing with same name, makes them the same variable. cause it print this:
2013-09-05 11:20:14.527 testIvar[12965:c07] FOO
2013-09-05 11:20:14.528 testIvar[12965:c07] FOO2
2013-09-05 11:20:14.529 testIvar[12965:c07] 1:FOO2 - 2:FOO2
even if i use %p to print the address memory of text and self.text i get the same address
*my other app test is this *
AppDelegate.h
#import <UIKit/UIKit.h>
#interface AppDelegate : UIResponder <UIApplicationDelegate>
{
NSManagedObjectContext *managedObjectContext;
NSManagedObjectModel *managedObjectModel;
NSPersistentStoreCoordinator *persistentStoreCoordinator;
}
#property (strong, nonatomic) UIWindow *window;
#property (readonly, strong, nonatomic) NSManagedObjectContext *managedObjectContext;
#property (readonly, strong, nonatomic) NSManagedObjectModel *managedObjectModel;
#property (readonly, strong, nonatomic) NSPersistentStoreCoordinator *persistentStoreCoordinator;
- (void)saveContext;
- (NSURL *)applicationDocumentsDirectory;
#property ( strong, nonatomic ) UINavigationController *navigationController;
#end
AppDelegate.m
#import "AppDelegate.h"
#import "MasterViewController.h"
#implementation AppDelegate
#synthesize managedObjectContext = managedObjectContext;
#synthesize managedObjectModel = managedObjectModel;
#synthesize persistentStoreCoordinator = persistentStoreCoordinator;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
MasterViewController *masterVC = [[MasterViewController alloc]initWithNibName:#"MasterViewController" bundle:nil];
masterVC.MOC = managedObjectContext;
self.navigationController = [[UINavigationController alloc]initWithRootViewController:masterVC];
[self.window setRootViewController:self.navigationController];
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
this app won't work if i do
masterVC.MOC = managedObjectContext;
but only work if i do
masterVC.MOC = self.managedObjectContext;
even if i print the mem address of managedObjectContext and self.managedObjectContext
i get 2 different addresses
how is that possible? same thing in 2 different app, behave in 2 different way?!?!?!?!?!?!?!?!?

Answer 1

masterVC.MOC = self.managedObjectContext; only works because the getter method has been overridden in that case.
See carefully and you will find that in your AppDelegate, there is a method
- (NSManagedObjectContext *)managedObjectContext
When you refer the object by self., the overridden getter method is called.