Question

I have a dictionary instance declared in PageOneView.h:

@interface PageOneView : UIViewController <UITableViewDataSource, 
                                           UITableViewDelegate, 
                                           UITextFieldDelegate>
{
    NSDictionary *orderDetailsDictionary ;
}
@property  (nonatomic, retain )NSDictionary *orderDetailsDictionary;

I synthesize it in PageOneView.m:

@implementation PageOneView

@synthesize orderDetailsDictionary;

I initialize it with an object returned by JSONSerialization class. (orderDetailsJSON is a JSON string I have read from a web service) This line is borrowed from the Apple sample code:

orderDetailsDictionary = [NSJSONSerialization JSONObjectWithData:
[orderDetailsJSON dataUsingEncoding:NSUTF8StringEncoding] options:0 error:nil];

Next I try to get the first key.

NSString *valString = [NSString stringWithFormat:
           @"%@\n", [[orderDetailsDictionary allKeys] objectAtIndex:0]];

allKeys crashes here with Program received signal: EXC_BAD_ACCESS. the output screen shows:

-[__NSCFArray allKeys]: unrecognized selector sent to instance 0x6a211d0

Answer 1

Obviously, orderDetailsDictionary is not a NSDictionary, but a NSArray. You should check the data coming from your server.