CODEWITHSUNDEEP
iosobjective-c
Vaiden
Vaiden

Reputation: 16132

Instance variables not nil after instantiateViewControllerWithIdentifier?

I have a class called ContentViewControllerPartial extending UIViewController. I instantiate it several times using content = [self.storyboard instantiateViewControllerWithIdentifier:@"ContentViewControllerPartial"]; expecting to get a new instance each time.

In my class I have an instance variable:

@implementation ContentViewController ... AVPlayer* mPlayerAV;

which is instanciated during viewDidLoad:

- (void)viewDidLoad {
    [super viewDidLoad];
    ...
    if ( !mPlayerAV )
    {
       mPlayerAV = [AVPlayer playerWithURL: videoURL];
    }

To my surprise, each of my ContentViewControllerPartial classes shared the same instance of mPlayerAV! This was obvious by the fact that it was not nil on the 2nd and 3rd instancations.

Only when I have turned mPlayerAV to a property, I got the expected behaviour - mPlayerAV was no longer shared between instances, and was nil.

What is going on here? How come a private instance variable is shared between instances?

Upvotes: 0

Views: 103

Answers (1)

Skyler Lauren
Skyler Lauren

Reputation: 3812

If you don't put your instance variables in {} it creates a global instead of an instance variable.

The post here does a great job of do's and don'ts for iVars.

Judging by the code provided I believe this explains the odd behavior. I hope that helps.

Upvotes: 1

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