Question

I don’t understand why I’m getting a EXC BAD ACCESS error when I call the mineHit method in my .m file. I understand that it’s indicating that the button array has been released, but I don’t understand why It would have been released at all.

#import "basicsViewController.h"

@implementation basicsViewController
@synthesize resetGame;
@synthesize scoreLabel;
@synthesize timeLabel;
@synthesize time;
@synthesize score;

-(void)newGame{
int index=0;
int yAxis=70;
for(int y=0;y<100;y=y+10){
    int xAxis=20;
    for( int x = 1; x < 11; x++) {
        buttonArray[index] = [[UIButton alloc]init];
        buttonArray[index] = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        [buttonArray[index] setTag:index];
        [buttonArray[index] addTarget:self action:@selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
        buttonArray[index].frame = CGRectMake(xAxis, yAxis, 26.0, 26.0);
        NSLog(@"tag:%d xAxis:%d yAxis:%d",buttonArray[index].tag,(int)buttonArray[index].frame.origin.x,(int)buttonArray[index].frame.origin.y);
        [self.view addSubview:buttonArray[index]];
        xAxis=xAxis+28;
        index=x+y;
    }
    yAxis=yAxis+28;
}

//generate bombs

for (int bombs=0;bombs<10;bombs++){

    bombArray[bombs]= (arc4random()%99);
    //TODO compare against bombArray to make sure of no duplicates
    NSLog(@"BOMB AT %d",bombArray[bombs]);

}

}



- (IBAction)resetPress:(id)sender {
[self newGame];
}


- (void)buttonClicked:(UIButton*)button
{
BOOL hit;
NSLog(@"SELECTED BUTTON:%d",button.tag);
for (int b=0;b<10;b++){
    if (button.tag==bombArray[b]){
        //BOMB HIT
        hit=YES;
        b=10;
    }
    else {
        //no bomb
        hit=NO;
    }
}
if (hit==YES){
    //if hit
    NSLog(@"HIT AT %d",button.tag);
    [self mineHit];

}
else {
    //if not hit
    NSLog(@"%d is clean",button.tag);
    [self cleanHit:button];

}
}

-(void)mineHit{

for (int d=0;d<100;d++){
    NSLog(@"%i",buttonArray[d].tag);
    buttonArray[d].enabled=NO;
    [buttonArray[d] setTitle:@"*" forState:UIControlStateDisabled];
}

}
-(void)cleanHit:(UIButton*)button{
button.enabled=NO;
[button setTitle:@"!" forState:UIControlStateDisabled];

}

- (void)viewDidLoad
{
[super viewDidLoad];
[self newGame];

}

- (void)viewDidUnload
{
[self setResetGame:nil];
[self setScoreLabel:nil];
[self setTimeLabel:nil];
[super viewDidUnload];

}
@end

Here is my .h file

#import <UIKit/UIKit.h>
NSInteger bombArray[];
UIButton *buttonArray[];
@interface basicsViewController : UIViewController
@property (weak, nonatomic) IBOutlet UIButton *resetGame;
@property (weak, nonatomic) IBOutlet UILabel *scoreLabel;
@property (weak, nonatomic) IBOutlet UILabel *timeLabel;
@property int time;
@property int score;
-(void)newGame;
-(void)buttonClicked:(UIButton*)button;
-(void)mineHit;
-(void)cleanHit:(UIButton*)button;

@end

Answer 1

When I compile your code I get four warnings. All four warnings are the same and say:

Tentative array definition assumed to have one element

The warnings apply to the definition of your bombArray and buttonArray arrays in the interface (.h) file.

If we give the two arrays a size your -mineHit method works fine.

Change the beginning of your .h file to:

#import <UIKit/UIKit.h>
NSInteger bombArray[10];
UIButton *buttonArray[100];
@interface basicsViewController : UIViewController

The compiler generates warnings for a reason and it is a good idea to try and get your code to compile cleanly with no warnings or errors.

Update: While we are here there is no reason why you couldn’t move these arrays inside the interface and declare them as instance variables. Doing this would mean that the arrays are associated with an individual instance of the view controller. It is unlikely that you’d have multiple instances of this view controller but it is better to do it correctly now than get bitten later.

#import <UIKit/UIKit.h>

@interface basicsViewController : UIViewController {
    NSInteger bombArray[10];
    UIButton *buttonArray[100];
}

Interestingly, moving the declaration into the interface turns the warnings into errors.