Question

I am having trouble creating a type of my custom class Frank. When I do I receive the following error:

Class method ‘+initWithWorld::’ not found (return type defaults to
‘id’)

My class is defined as so:

@interface Frank : NSObject {
    PhysicsSprite *frankSprite;
    b2Body *body;

    float weight;
}

@property (readonly) b2Body *body;

-(void)initWithWorld:(b2World *) world :(CCNode *)parent;

-(void)moveLeft;
-(void)moveRight;

@end

I create the object like so:

frank = [Frank initWithWorld:world :self];

What am I doing wrong?

Answer 1

An object needs to be allocated first:

frank = [ [ Frank alloc ] initWithWorld: world :self ];

Your init method is a member method (width a - sign), meaning you need to call it on an allocated object, as opposed to class methods (with a + sign).

Edit

As pointed by @JustSid, such an init method must also return an object (type id).
So the correct method prototype is:

- ( id )initWithWorld: ( b2World * )world : ( CCNode * )parent;

The implementation should then be something like:

- ( id )initWithWorld: ( b2World * )world : ( CCNode * )parent;
{
    if( ( self = [ self init ] ) )
    {
        /* Your initialisation here */
    }

    return self;
}