CODEWITHSUNDEEP
iphoneiosobjective-cxcode
Brandon
Brandon

Reputation: 2171

Global Variable pulled from App Delegate

I am trying to use a variable integer throughout multiple methods in my view controller. The secondsLeft variable works fine, but the otherNumber variable won't work. I get the error: initializer element is not a compile-time constant. Any ideas on how I am supposed to do this? THank you!

@interface ViewController ()

@end

@implementation ViewController
@synthesize countDown,Timerlbl;

int secondsLeft = 500;

int otherNumber =[(AppDelegate *)[UIApplication sharedApplication].delegate otherNumber];

Upvotes: 0

Views: 3271

Answers (3)

Stuart Sharpe
Stuart Sharpe

Reputation: 601

You can't declare a variable like this because the compiler can't create an instance of AppDelegate and ask it what the value of otherNumber should be.

Depending on how it's being used, it might be better not to define the otherNumber variable at all, and instead retrieve it from AppDelegate each time it is used. This might mean a little more typing, but it does mean you'll always get the latest correct value of otherNumber

Also, it's a good idea in general to use NSInteger instead of int when defining integer variables.

Upvotes: 0

Mike Kwan
Mike Kwan

Reputation: 24477

The problem is that you have declared otherNumber as a global variable and the compiler expects the initial assignment to be a compile-time constant. [delegate otherNumber] results in a selector invocation and this is not a compile-time constant.

The solution is to move the assignment into code. For example:

- (id)init
{
    self = [super init];
    if(self) {
        otherNumber = [(AppDelegate *)[UIApplication sharedApplication].delegate otherNumber];
    }

    return self;
}

As another note, global variables are generally inadvisable in Objective-C. @property values are generally more recommended. Not only that, your ViewController class now has a dependency with your AppDelegate. Since your AppDelegate most likely is the one responsible for instantiating your ViewController, consider having it inject in the value of otherNumber. For example:

@interface ViewController ()
@property (nonatomic, assign) int otherNumber;
@end

- (id)initWithSomeNumber:(int)otherNumber
{
    self = [super init];
    if(self) {
        self.otherNumber = otherNumber;
    }

    return self;
}

Upvotes: 2

Flexicoder
Flexicoder

Reputation: 8511

I assume that AppDelegate is the name of your app delegate class?

Have you tried adding an import for your AppDelegate, like this...

#import "AppDelegate.h"

@interface ViewController ()

Upvotes: 0

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