In Crystal Ball app Labels disappear when button is pressed....

When I am running the code, it's not giving me any error but when I am pressing the button, I am having blank labels, though my code is exactly the same. Has anyone came across the same issue? does anyone know the solution to this? Responses and suggestions will be appreciated....Thanks. Here is my code.......

ViewController.h :-

import <UIKit/UIKit.h>

@class CrystalBallModel; @interface ViewController : UIViewController

@property (weak, nonatomic) IBOutlet UILabel *predictionLabel; @property (strong,nonatomic) CrystalBallModel *crystalBall;

-(IBAction)buttonPressed;

@end

ViewController.m :-

import "ViewController.h" import "CrystalBallModel.h"

@interface ViewController ()

@end

@implementation ViewController

-(void)viewDidLoad { [super viewDidLoad]; self.crystalBall = [[CrystalBallModel alloc]init]; } -(void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; } -(IBAction)buttonPressed { self.predictionLabel.text = [self.crystalBall randomPrediction]; } @end

CrystalBallModel.h :-

import <Foundation/Foundation.h> @interface CrystalBallModel : NSObject { NSArray *_predictions; }

@property (strong,nonatomic,readonly) NSArray *predictions;

-(NSString*) randomPrediction;

@end

CrystalBallModel.m :-

import "CrystalBallModel.h"

@implementation CrystalBallModel

-(NSArray*) _predictions{

if (_predictions == nil) {

_predictions = [[NSArray alloc] initWithObjects:@"it is decidedly so", @"it is certain", @"The stars are not aligned", @"It is doubtful", @"Better not tell you now", @"Concentrate and ask again", nil]; } return _predictions; }

-(NSString*) randomPrediction{

int random = arc4random_uniform((uint32_t)self.predictions.count);

return [self.predictions objectAtIndex:random]; } @end

Anyone is facing the same issue? any solution to that?