NSUserDefaults overriding previously saved values - ios

Question

I have two completely separate tasks being carried out but somehow they seem to connect.
In ViewController 1, I have:
NSString *foo = #"foo";
NSUserDefaults *default1 = [NSUserDefaults standardUserDefaults]
[default1 setObject:foo forKey:#"foo"];
[default1 synchronize];
and when I do:
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"foo"]);
The value printed is what I expect it to be.
In ViewController 2, I have:
NSString *bar = #"bar";
NSUserDefaults *default2 = [NSUserDefaults standardUserDefaults]
[default2 setObject:bar forKey:#"bar"];
[default2 synchronize];
And same again when I NSLog it, the value is what I expect it to be.
But somehow when i try to print object #"foo" again it gives me the value for the second object, in this case #"bar"
Any guidance on why my original value is being overridden by the second value even tough the variable/key names are different in the 2 classes?

Answer 1

You are doing this for both:
[foo setObject:bar forKey:#"bar"];
Shouldn't it be:
[defaults1 setObject:foo forKey:#"foo"];
And
[defaults2 setObject:bar forKey:#"bar"];
There is however, a greater problem:
NSString *foo = #"foo";
NSUserDefaults *default1 = [NSUserDefaults standardUserDefaults];
[default1 setObject:foo forKey:#"foo"];
[default1 synchronize];
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"foo"]);
NSString *bar = #"bar";
NSUserDefaults *default2 = [NSUserDefaults standardUserDefaults];
[default2 setObject:bar forKey:#"bar"];
[default2 synchronize];
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"bar"]);
Will work properly, however you're creating defaults1 and defaults2 which are both instances of standard defaults, so:
NSUserDefaults * defaults1 = [NSUserDefaults standardUserDefaults];
NSUserDefaults * defaults2 = [NSUserDefaults standardUserDefaults];
[NSUserDefaults standardUserDefaults];
Are all pointers to the standardUserDefaults singleton. So they are identical instances. You could simply do:
NSUserDefaults *standardDefaults = [NSUserDefaults standardUserDefaults];
NSString *foo = #"foo";
[standardDefaults setObject:foo forKey:#"foo"];
NSString *bar = #"bar";
[standardDefaults setObject:bar forKey:#"bar"];
[standardDefaults synchronize];
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"foo"]);
NSLog(#"%#", [[NSUserDefaults standardUserDefaults] objectForKey:#"bar"]);

Answer 2

You can print out the entire set of user defaults with code like this
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
NSDictionary *dictionary = [defaults dictionaryRepresentation];
NSLog( #"%#", dictionary );
Note that Apple puts lots of garbage in the user defaults, so you'll have to scroll to the end to see foo and bar. I'm guessing that you have a typo in code that you haven't shown us, and either foo is being overwritten, or foo simply isn't being displayed properly.
The current code in your question (after 1 edit) is all good and should work correctly.