EXC_BAD_ACCESS on NSMutableArray insertion - iphone

Question

I am using an NSMutableArray defined in a CCLayer subclass as follows:
//
// GameOverScene.h
// Cocos2DSimpleGame
//
// Created by Ray Wenderlich on 2/10/10.
// Copyright 2010 Ray Wenderlich. All rights reserved.
//
#import "cocos2d.h"
#interface scoLayer : CCColorLayer {
CCLabelTTF *_label;
CCLabelTTF *_howtoplay;
NSMutableArray *highscores;
}
#property (nonatomic, retain) CCLabelTTF *label;
#property (nonatomic, retain) NSMutableArray *highscores;
#property (nonatomic, retain) CCLabelTTF *back;
+ (id)initWithScore:(int)lastScore;
+(void)print_label:(int)lb;
+(void)menu;
#end
#interface sco : CCScene {
scoLayer *_layer;
}
#property (nonatomic, retain) scoLayer *layer;
#end
Here is the .m file for the class:
#implementation sco
#synthesize layer = _layer;
- (id)init {
if ((self = [super init])) {
self.layer = [scoLayer node];
[self addChild:_layer];
}
return self;
}
- (void)dealloc {
[_layer release];
_layer = nil;
[super dealloc];
}
#end
#implementation scoLayer
#synthesize label = _label;
#synthesize highscores ;
//#synthesize how_to_play ;
#synthesize back;
-(id) init
{
if( (self=[super initWithColor:ccc4(255,255,255,255)] )) {
CGSize winSize = [[CCDirector sharedDirector] winSize];
self.label = [CCLabelTTF labelWithString:#"" fontName:#"Arial" fontSize:16];
//self.how_to_play = [CCLabelTTF labelWithString:#"" fontName:#"Arial" fontSize:32];
self.highscores = [[NSMutableArray alloc] initWithObjects:nil ];
// [highscores addObject:#"asdf"];
// NSLog(#"hig %#", [highscores objectAtIndex:0]);
_label.color = ccc3(0,0,0);
_label.position = ccp(winSize.width/2, winSize.height/2);
[self addChild:_label z:100];
[self runAction:[CCSequence actions:
[CCDelayTime actionWithDuration:3],
[CCCallFunc actionWithTarget:self selector:#selector(gameOverDone)],
nil]];
CCSprite *bk1 =[CCSprite spriteWithFile:#"bg3.png" ];//rect: CGRectMake(0, 0, 40, 480)];
[bk1 setPosition:ccp(160, 239)];
[self addChild:bk1 z:0];
CCMenuItem *back = [CCMenuItemImage
itemFromNormalImage:#"gameBackButton.png" selectedImage:#"gameBackButton.png"
target:self selector:#selector(back_game:)];
CCMenu *menu1 = [CCMenu menuWithItems:back,nil];
menu1.position = ccp(70, 100);
[menu1 alignItemsVerticallyWithPadding: 40.0f];
// [self addChild:menu z: 2];
[self addChild:menu1 z: 0];
}
return self;
}
In this function:
+(id)initWithScore:(int)lastScore
{
NSLog(#"score %d", lastScore);
//NSMutableArray *highscores = [[NSMutableArray alloc] initWithObjects:nil ];
//[highscores addObject:#"asdf"];
if([highscores count] == 0)
}
I want to use the highscores array and insert the data (lastScore), but when I do this the application exits with an EXC_BAD_ACCESS signal. How can I fix this error?

Answer 1

The + before the method declaration indicates, that this is a class method. So you have no access to instance variables.
I think this is more what you want:
-(id)initWithScore:(int)lastScore
{
NSLog(#"score %d", lastScore);
if(!self = [super init])
return nil;
highscores = [[NSMutableArray alloc] init];
[highscores addObject:lastScore];
return self;
}

Answer 2

You're on the right track, but unless you have many different highscore tables you don't need to make it a separate class, as you've tried to do now. (I.e. 'create many highscore table instances with a class'.) You can of course use a class and create an object of class highscoretable at [[alloc] init] (as yan kun shows), but if all you need is a mutable array to add highscores to in your game, just allocate one in the app delegate, or use other methods for variables shared between viewcontrollers, I think.