Accessing a NSMutableArray from another class

I have a NSMutableArray and I need to access it from another class. This is what I have done so far;

1. I declared NSMutableArray *muArr in the .h file, and @property(nonatomic, retain) NSMutableArray *muArr.

2. @synthasize muArr; in the .m file, and finally populated it: 开发者_StackOverflow中文版

   [muArr addObject: @"First"];

3. Now in SecondView I added the import statement #import "FirstView.h" and wrote: FirstView *frv = [[FirstView alloc]init]; then NSLog(@"%i",[frv.muArr count]);

These lines of code are written in the viewDidLoad method. and when the NSLog was printed I got 0 records instead of 1.

Why is this? what have I done wrong, and can someone show me a sample code/tutorial?

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You are populating muArr in didSelectRowAtIndexPath, which doesn't get called until you select a row. By calling init on your FirstView, you create a new FirstView then immediately check the count of muArr. The count is 0, because you haven't selected any rows yet..

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You need to create a property(in the same fashion as you create muArr) in SecondView class

Step 1) : Lets say arrOfSecondView and you synthesize it

Step 2) Now you can add your muArr data to arrOfSecondView

   SecondView *secondView = [[SecondView alloc]init];
   secondView .arrOfFirstView = muArr;
   //and i guess you are pushing to secondView controller

Step 3) Check the arrOfFirstView count

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Do you allocate the array? Before you add items to it, you have to allocate it with

myArr = [[NSMutableArray alloc] init];

If you don't do that, the [addObject] call will not crash the program, but won't have any effect. And array's count will remain zero forever.

@synthesize, contrary to a popular belief, does not allocate the ivar. It just generates a getter method and, optionally, a setter method in the class.