如何在按下按鈕時在NSMutableArray中添加值

Question

對於我的iOS應用程序我想啓動一個NSMutableArray，並在運行時用按鈕更改數組保存的對象。到目前爲止，我能夠在ViewController.m中的viewDidLoad {}中啓動一個數組，但現在我無法在我的buttonPressed方法中訪問它。我怎樣才能讓數組訪問保存文件？

#import "ViewController.h" 

@interface ViewController() 

@end 

@implementation ViewController 

- (void)viewDidLoad { 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view. 
    NSMutableArray *toCalculate = [@[@0] mutableCopy]; 
} 


- (IBAction)numbersButtonsPressed:(UIButton *)sender { 
    NSLog(@"%ld\n", sender.tag); 
    [toCalculate addObject:[NSNumber numberWithLong:sender.tag]]; 
} 

Answer 1

聲明變量爲全局（類變量）不是局部變量（函數）。

What is global variable?

解決方案的問題是：

#import "ViewController.h" 

@interface ViewController(){ 
    NSMutableArray *toCalculate; 
} 
@end 

@implementation ViewController 

- (void)viewDidLoad { 
    [super viewDidLoad]; 
    toCalculate = [@[@0] mutableCopy]; 
    // Do any additional setup after loading the view, typically from a nib. 
} 



- (IBAction)numbersButtonsPressed:(UIButton *)sender { 
    NSLog(@"%@",toCalculate); 
    [toCalculate addObject:[NSNumber numberWithLong:sender.tag]]; 
} 


@end 

Answer 2

感謝保羅， 它的工作，如果你實現它作爲ViewController.h文件@property他說的那樣。

@interface ViewController: UIViewController 

    @propety NSMutableArray *giveItAName 

    @end