NSDictionary valueForKey crash

Question

How can i retrieve the key value from the below NSMutableArray array. The below code crashes on isEqualToString. However i can see the value of nsRet in the variable view window as @\x18\xaa\x01\xc8\a before running that statement.

        NSMutableArray* nsMyList = [[NSMutableArray alloc] init];
        [nsMyList addObject:[NSDictionary dictionaryWithObjectsAndKeys:
                             @"valueOfKey", @"Key",
                             nil]];
        NSString *nsRet = [nsMyList valueForKey:@"Key"];
        if ([nsRet isEqualToString:@"deviceClass"])
        {
            NSLog(@"Key value:%@", nsRet);
        }

Can anyone here please help me get the correct value for the key? Thanks.

Answer 1

This is because you need objectForKey:, not valueForKey:. The valueForKey: method is for key-value programming. Moreover, the call should be on the [nsMyList objectAtIndex:0], like this:

NSString *nsRet = [[nsMyList objectAtIndex:0] objectForKey:@"Key"]

Answer 2

You've stored the NSDictionary in an array. The correct access based on your code would be:

NSDictionary *dict = [nsMyList objectAtIndex:0];
nsret = [dict valueForKey:@"Key"];

Answer 3

It looks like you are trying to get the valueForKey: on an NSMutableArray rather than on the dictionary.

What you want is:

[[nsMyList objectAtIndex:0] valueForKey:@"Key"];

Answer 4

I am a bit lost.

In order to access the dictionary you just create you need to obtain the first element in the NSMutableArray and then the dictionary.

It will be something like this:

NSString *nsRet = [nsMyList[0] objectForKey:@"Key"]

I think it can solve it.