Question

In my iPhone app.

I am copying the one mutable array(with dictionary) to another.

It is like

resultsToDisplay = [[[NSMutableArray alloc]initWithArray:resultsPassed]mutableCopy];


  2012-06-21 17:07:07.441 AllinoneCalc[3344:f803] Results  To Display (
        {
        lbl = "Monthly EMI";
        result = "75.51";
    }
)
2012-06-21 17:07:08.224 AllinoneCalc[3344:f803] Results Passed (
        {
        lbl = "Monthly EMI";
        result = "75.51";
    }
)

Then I am modifying one of them .

[[resultsToDisplay objectAtIndex:i] setValue:[NSString stringWithFormat:@"%.2f",[[[resultsPassed objectAtIndex:i] valueForKey:@"result"] floatValue]] forKey:@"result"];

But what is happening that both are getting edited.

2012-06-21 17:07:08.703 AllinoneCalc[3344:f803] Results Passed (
        {
        lbl = "Monthly EMI";
        result = "75.00";
    }
)
2012-06-21 17:07:08.705 AllinoneCalc[3344:f803] Results  To Display (
        {
        lbl = "Monthly EMI";
        result = "75.00";
    }
)

They both are referring to the same copy.

How to solve this. I want to modify only one array.

Answer 1

You are only copying the array of object pointers, not the object themself. See this article on deep copying.