Is this a memory leak?

Question

I have something similar to this.

initMyclass {
 if (self= [super init]) {
   classMember = [[NSMutableArray alloc] init];
 }
 return self;
}

Instruments reports a leak there.

I'm leaking memory there ? If not, xcode reports false memory leaks ?

Thanks.

Answer 1

Instruments is reporting the leak there because you're not releasing the object elsewhere. You need to have [classMember release] in that class's dealloc method:

- (void) dealloc {
  [classMember release];
  [super dealloc];
}

Answer 2

This is why you should use properties or explicit accessors.

If you had this:

@interface myObject : NSObject
{
    NSMutableArray *classMembers;
}
@property(nonatomic, retain)  NSMutableArray *classMembers;

@end

@implementation myObject
@synthesize classMembers;

-(id) init{
    if (self=[super init]) {
        self.classMembers=[[NSMutableArray alloc] initWithCapacity:1];
    }
    return self;
}//-------------------------------------(id) init------------------------------------

-(void) dealloc{
    [classMembers release];
    [super dealloc];
}//-------------------------------------(void) dealloc------------------------------------

@end

You would not (and should not ever) have to miss around with the retention of a property. This eliminates all leaks and over-releasing of properties.

If the property's object leaks, then you know automatically it is being retained in another object other than the instance of the class containing the property.

Answer 3

Is it a class or instance member? Show us the @interface for this class.

Also, initMyClass .. or something .. is not a proper init method. It's signature should be of the form:

- (id) init {
    if ((self = [super init]) != nil) {
        someInstanceVariable = [NSMutableArray new];
    }
    return self;
}

Be more specific when you ask a question here.