NSDictionary - need to obtain value for key subelement

Question

I have created an NSDictionary named "myData" which contains the following JSON response:

{
listInfo =     (              
{ 
    date = 1392157366000;       
    dateAsString = "02/11/2014 22:22:46";     
    id = 6;  
    address = 542160e0000c;     
    myLevel = 13;  
},            
{

    date = 1392155568000;        
    dateAsString = "02/11/2014 21:52:48";      
    id = 5;    
    address = 542160e0000c;     
    myLevel = 13;

}
    );
}

I need to retrieve each of the [dateAsString] key/value pairs. I've tried: NSString *dateAsString=[[myData valueForKeyPath:@"dateAsString"][0] objectForKey:@"myData"]; without any luck.

Any suggestions are greatly appreciated.

Go to json.org and learn the JSON syntax. It only takes 5-10 minutes. Then ***look*** at what you have. You erroneously omitted the leading `{` in the dump indicating the start of a dictionary. The only element in the dictionary is "listInfo". The value of that element is an NSArray (as indicated by the `()` brackets), and that array contains 2 dictionaries (bracketed by `{}`). If you take it one step at a time it's incredibly easy to take that apart and extract the data. — Hot Licks, May 15 '14 at 23:50

score 2 · Accepted Answer · answered May 15 '14 at 20:10

2

I think this will work:

NSArray* dateStringArray = [listInfo valueForKeyPath:@"@unionOfObjects.dateAsString"]

I believe it will give you an array of strings. If you need to stuff that back in a dictionary, that should be fairly easy.

It's not clear what your "myData" looks like... so I used the listInfo array of dicts shown.

answered May 15 '14 at 20:10

stevesliva

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I think "listInfo" is the first and only key in an outer dictionary, so it would be something like `[myData valueForKeyPath:@"listInfo.dateAsString"]`. – Chuck May 15 '14 at 23:07
Actually, `[myData valueForKeyPath:@"listInfo.@unionOfObjects.dateAsString"]` if that is the case – stevesliva May 16 '14 at 01:19
@stevesliva - Thanks for your response. Actually, the "myData" dictionary contains the listInfo dictionary. – Native_Mobile_Arch_Dev May 16 '14 at 13:05
@Chuck - Thanks Chuck, this is the solution I will use. – Native_Mobile_Arch_Dev May 16 '14 at 13:13
All you wanted was a path to a single element?! – stevesliva May 16 '14 at 16:08
Which incidentally would be `myData[@"listInfo][0][@"dateAsString"]` Using @unionOfObjects in the keyPath gives you an array for the middle [0] – stevesliva May 16 '14 at 17:19

NSDictionary - need to obtain value for key subelement

1 Answers1