Can i have a single NSMutableArray in my multiple views application?

Question

I have a navigational based application which has multiple views. Is it possible to use one single NSMutableArray for the whole applicaiton? Can i add objects to that NSMutableArray in one view and then remove object from the same NSMutableArray from some other view? I tried

 myappAppDelegate *appDelegate = (myappAppDelegate *)[[UIApplication sharedApplication] delegate];

but it gives me null when i try to access appDelegate's array. If anyone can give me any idea or helping link or tutrorial. Thanks in advance.

Answer 1

If you are having multiple views in your application, and in that case you want to have a variable accessible to every view, you should always create a Model/Data(singleton) class and define the variable in it. Something like this :

//DataClass.h      

@interface DataClass : NSObject {    

NSMutableArray *arrGlobal;     

}    
@property(nonatomic,retain)NSMutableArray *arrGlobal;   
+(DataClass*)getInstance;    
@end  



//DataClass.m    
@implementation DataClass    
@synthesize arrGlobal;    
static DataClass *instance =nil;    
+(DataClass *)getInstance    
{    
    @synchronized(self)    
    {    
        if(instance==nil)    
        {    

            instance= [DataClass new];    
        }    
    }    
    return instance;    
}    

Now in your view controller you need to call this method as :

DataClass *obj=[DataClass getInstance];  
obj.arrGlobal = arrLocal; 

This variable will be accessible to every view controller. You just have to create an instance of Data class.