expected ';' at end of declaration list objective c - objective-c

Question

"error: expected ';' at end of declaration list" objective c
When I am trying to declare global variable
#implementation CachingManager{
NSMutableArray*object = [[NSMutableArray alloc] init];
}

Answer 1

You can create instance variables here but cannot initialize those instance variables here like you do. They are all initialized to nil or zeroes. So compiler expect a semicolon when you are writing an equal sign.
You can initialize them in init method or other method where your class initialization takes place in order to make them global variables. e.g.
Interface block for instance variable inside .m file:
#interface CachingManager ()
{
// instance variables initialized to nil or zeroes
NSMutableArray *object; // global ivar
}
#end
Implementation part same .m file:
#implementation CachingManager
- (void)viewDidLoad {
[super viewDidLoad];
object = [[NSMutableArray alloc] init]; // initialization takes place
}

Answer 2

One way to implement global variables, and to manage their lifetime (i.e. that they are initialised) and even to provide global methods is to implement a class exposing those variables/methods and to use the singleton pattern:
yourFile.h:
#import <Foundation/Foundation.h>
#interface GlobalVars : NSObject
{
NSMutableArray *_truckBoxes;
NSMutableArray *_farmerlist;
NSString *_farmerCardNumber;
NSString *_fName;
}
+ (GlobalVars *)sharedInstance;
#property(strong, nonatomic, readwrite) NSMutableArray *truckBoxes;
#property(strong, nonatomic, readwrite) NSMutableArray *farmerList;
#property(strong, nonatomic, readwrite) NSString *farmerCardNumber;
#property(strong, nonatomic, readwrite) NSString *fName;
#end
yourFile.m:
#import "GlobalVars.h"
#implementation GlobalVars
#synthesize truckBoxes = _truckBoxes;
#synthesize farmerList = _farmerList;
#synthesize frameCardNumber = _frameCardNumber;
#synthesize fName = _fName;
+ (GlobalVars *)sharedInstance {
static dispatch_once_t onceToken;
static GlobalVars *instance = nil;
dispatch_once(&onceToken, ^{
instance = [[GlobalVars alloc] init];
});
return instance;
}
- (id)init {
self = [super init];
if (self) {
_truckBoxes = [[NSMutableArray alloc] init];
_farmerlist = [[NSMutableArray alloc] init];
// Note these aren't allocated as [[NSString alloc] init] doesn't provide a useful object
_farmerCardNumber = nil;
_fName = nil;
}
return self;
}
You can then use these global variables like this, for example:
GlobalVars *globals = [GlobalVars sharedInstance];
globals.fName = #"HelloWorld.txt";
[globals.farmerList addObject:#"Old Macdonald"];
[self processList:[globals farmerList]];
However, please consider:
You don't need to use global variables like this; you should be able to create a model object which is created as necessary and reference to it passed to the views. This is MVC.
You also posted a stack trace of an unrelated issue which is extremely common with Objective-C; only you can fix this error, once you realise what it is.

Answer 3

That sin't a global variable. That would be an instance variable and that particular syntax wasn't commonly used after 2005 (really, it wasn't terribly common after the mid 90s).
If you want a global variable, do:
NSMutableArray *myGlobal;
Somewhere at the top level -- at the same level with the #implementation -- of your source.
You'll have to initialize the global variable elsewhere, though. Typically, in the +initialize or +load method of the class.