cannot init a class object : objective-C

Question

I'm trying to make a simple subclass of CCNode, but I can't create the object.

It gives me the error "* Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* +[ContentPane<0x206898> init]: cannot init a class object.'"

Here is my subclass of CCNode:

#import "ContentPane.h"

@implementation ContentPane{
    int content[8][4];
    CCSprite *_rockPath1;
    CCSprite *_rockPath2;
}

- (id)init {
    self = [super init];

    if (self) {
        CCLOG(@"ContentPane created");
    }

    return self;
}

@end

Here is where I try to initiate it:

- (void)didLoadFromCCB {
    // tell this scene to accept touches
    self.userInteractionEnabled = TRUE;
    _counter = 0;
    ContentPane *pane = [ContentPane init];
}

cream-corn · Accepted Answer · 2014-08-14T00:18:08.103

36

Couple things,

In Obj-c when you want to initialize an Object, you need to allocate space for it. That is done using the alloc keyword.

so your ContentPane *pane = [ContentPane init];

turns into ContentPane *pane = [[ContentPane alloc] init];

Also, whatever tutorial you are following, Stop... the way you have declared your variables we call them (iVars) is a very old fashioned way of doing things, they should really be properties. and Boolean values are represented by YES and NO not TRUE and FALSE

edited Aug 14 '14 at 00:18

answered Aug 14 '14 at 00:11

cream-corn

1,820
14
26

Do I have to deallocate my objects later on? I'm confused by what the ARC does and doesn't handle. – Aeisys Aug 14 '14 at 00:43
1

sure, [Beginning iOS programming by Ray Wenderlich](http://www.raywenderlich.com/tutorials) is a really good resource. And any book that is less then a year old will really help too. Objective-c has matured a lot since the "old" days. ARC you generally do not have to worry about, IF you are using properties, properties do a lot for you for free. ARC (automatic reference counting) is exactly that, if a property is marked as `Strong` then it will increment the reference count, When that count becomes zero, your object will be free'd – cream-corn Aug 14 '14 at 00:49

score 1 · Answer 2 · answered Jan 23 '20 at 14:25

1

If you are here just like me wondering why you code is crashing.

 [NSArray init];

should be :

[[NSArray alloc] init];

or

[NSArray array];

You crash could caused by any other class here NSArray here is for reference only.

answered Jan 23 '20 at 14:25

Vigneshwaran Murugesan

747
4
19

cannot init a class object : objective-C

2 Answers2