How to make a global property (setter and getter)?

Question

I need to create an object for example NSString and let other classes get/set the value for it.

thx. for help :)

[What have you tried?](http://mattgemmell.com/2008/12/08/what-have-you-tried/) — Extra Savoir-Faire, Dec 06 '12 at 15:33
@Omarj try to rethink your class design and avoid global variables. — Pfitz, Dec 06 '12 at 15:42
Pass the object as a parameter to the other objects who need access to it. Maybe if you explain exactly what you need we'll be able to be more specific. — Eli Ganem, Dec 06 '12 at 15:42

score 4 · Accepted Answer · answered Dec 06 '12 at 15:34

4

The easiest way to do this is to attach the value as a property to a singleton instance of some class. One singleton instance that already exists in your application is the application delegate. So, just add an NSString property to your application delegate and you can access it from any class in your app (as long as you #import your application delegate).

In your application delegate:

@property(nonatomic, strong) NSString* someString;

In your other classes:

[self doSomethingWithAString:((YourAppDelegateClass*)[[UIApplication sharedApplication] delegate]).someString];

answered Dec 06 '12 at 15:34

eric.mitchell

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i don't need to use application delegate . – Omarj Dec 06 '12 at 15:37
No, you don't, but it's easier than having to create your own singleton class for just one object. – eric.mitchell Dec 06 '12 at 15:47
1

did this effect on application performance cause i have more than one variable and need retrieve it more than one ??? – Omarj Dec 06 '12 at 15:49
No there is no difference in performance using this technique – eric.mitchell Dec 06 '12 at 16:00

score 1 · Answer 2 · edited May 23 '17 at 10:34

1

Create a Singleton/Shared class.

@implementation SINGLETON

static SINGLETON *instance = nil;

+(SINGLETON*)sharedInstance{
    @synchronized(self) {   
        if (instance == nil) {
            instance = [[SINGLETON alloc] init];
        }
        return instance;
    }
 }

EDIT:

This will come handy... Objective-C Singleton problem. Object recognized in one class but not another

edited May 23 '17 at 10:34

Community

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1

answered Dec 06 '12 at 15:33

Anoop Vaidya

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this one just allow to me retrieve value Not set ?? – Omarj Dec 06 '12 at 15:36
1

it is not allow to do it like u say go and try it and you will see what i mean. – Omarj Dec 06 '12 at 15:38
@AnoopVaidya Your class method always returns nil. Fix it. – Extra Savoir-Faire Dec 06 '12 at 15:43

How to make a global property (setter and getter)?

2 Answers2