CODEWITHSUNDEEP
objective-cxcodewarnings
ICL1901
ICL1901

Reputation: 7778

Xcode warning "Property access results unused - getters should not be used for side effects"

I'm getting this warning when I'm calling a local routine.

My code is this:

-(void)nextLetter {
    // NSLog(@"%s", __FUNCTION__);
    currentLetter ++;
    if(currentLetter > (letters.count - 1))
    {
        currentLetter = 0;
    }
    self.fetchLetter;
}

I'm getting the warning on the self.fetchLetter statement.

That routine looks like this:

- (void)fetchLetter {
    // NSLog(@"%s", __FUNCTION__);
    NSString *wantedLetter = [[letters objectAtIndex: currentLetter] objectForKey: @"langLetter"];

    NSString *wantedUpperCase = [[letters objectAtIndex: currentLetter] objectForKey: @"upperCase"];    


.....   
}

I prefer to fix warning messages, is there a better way to write this?

Thanks!

Upvotes: 66

Views: 29292

Answers (4)

DarkDust
DarkDust

Reputation: 92335

In newer Xcode versions, even the [object method]; may trigger the warning. But sometimes we actually do need to call a property and discard the result, for example when dealing with view controllers and we need to make sure the view is actually loaded.

So we were doing:

// Ensure view is loaded and all outlets are connected.
[self view];

This now also triggers the “Property access results unused - getters should not be used for side effects” warning. The solution is to let the compiler know it's done intentionally by casting the result type to void:

(void)[self view];

Upvotes: 13

LAOMUSIC ARTS
LAOMUSIC ARTS

Reputation: 628

I just got my problem resolved, in my case a CoreLocation Project, using both answers from Tom and Chris -

I declare:

@property (strong, nonatomic)CLLocationManager *locationManager;

And implemented like:

@synthesize locationManager = _locationManager;
....
- (void) dealloc {
         [self locationManager];
}

Upvotes: 0

Chris Devereux
Chris Devereux

Reputation: 5473

You're declaring fetchLetter using syntax like this?

@property (retain) id fetchLetter;

That looks wrong for what you're doing. Properties are intended to be variable accessors that (in the case of getters) don't have any side effects.

You should declare fetchLetter as a method, like so:

- (void) fetchLetter;

and access it using:

[self fetchLetter]

Upvotes: 4

Tom Dalling
Tom Dalling

Reputation: 24125

The dot notation (i.e. self.fetchLetter) is meant for properties, not for arbitrary methods. The self.fetchLetter is being interpreted as "get the 'fetchLetter' property of 'self'," which isn't what you intend.

Just use [self fetchLetter] instead.

Upvotes: 134

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