how to fetch data from NSMutableArray ObjectAtIndex from integer value? [closed]

Your code hurt my eyes

There are certain coding standards to be followed while writing code in Objective-C. Every language got one. They make code readable and understandable. You can refer to Cocoa Coding Guidelines and help yourself writing better looking code.

Explain Properly

Without the error message before crash no one can help you. Next time when you post about a crash, also explain the error message you got.

Was it a EXEC_BAD_ACCESS? If so it is the awesome garbage collector sweeping your array object away. Anyway your code sores my eyes and I am taking the privilege refactoring the code. Maybe it will help you.

A little bit of refactoring

NSArray *aArray;
- (void)viewDidLoad
   {
     [super viewDidLoad];
     aArray = @[@"1", @"2", @"3", @"4"];
     // or use[[NSArray alloc]initWithObjects:@"1", @"2", @"3", @"4", @"5"];
     //Why do you need a mutable array while initializing it static?
   }

 - (void)methodSecond
   {
     static int counter = 0;
       if (aArray) {
         if (counter<aArray.count) {
           NSLog(@"A is %u",[[aArray objectAtIndex:counter++]integerValue]);
         } else {
           counter = 0;
           [self methodSecond];
         }
       }
   }

Understand what you are doing

So a detail explanation of what I guess your problem is:

• You're using [NSArray initWithObjects:] this creates an autoreleased object, and we got no control over its life time. And they get released if they are not referenced immediately after creating, which is probably whats happening your case. In my experience, mutable autoreleased object always sources bad access problems. So it is better to have the object alloc and inited, ie.. [[NSArray alloc]initWithObjects:] and I observe you are not adding/removing array members in run-time. There is no purpose of having a MutableArray.

• In your code, you're creating two objects. The first array object is allocated and immediately dereferenced in the next line. Which is probably a mistake.

If you want to know more about auto-released objects. Read this.

in your code you are usimng two different varaibles once check thosetwo.

var_Count_Answer and var_Count_Answer_A

This error occurs because you are using an auto-released object. When you call like:

A_array = [NSMutableArray arrayWithObjects:@"4",@"6",@"2",@"3",@"0",@"5",@"1",@"2",@"4",@"1",@"0",@"2",@"4",@"2",@"0",@"3",nil]

The A_array is an autoreleased object, you can't say when it'll be released. That is why this error occurs.

Solution:

Declare a property for the array like:

@property (nonatomic, strong) NSMutableArray *A_array;

Then modify your methods like:

-(void)ViewDidLoad
{
     _A_array = [NSMutableArray arrayWithObjects:@"4",@"6",@"2",@"3",@"0",@"5",@"1",@"2",@"4",@"1",@"0",@"2",@"4",@"2",@"0",@"3",nil]
    var_Count_Answer_A   = 0;    // int  
}

-(void)method_Second
{
    NSLog(@"%@",[_A_array objectAtIndex:var_Count_Answer_A])
    NSString *str1 = [[NSString alloc]initWithFormat:@"%@",[_A_array objectAtIndex:var_Count_Answer_A]];
    A = [str1 integerValue];
    NSLog(@"A is %d",A);
    var_Count_Answer_A ++;
}