Importing JSON objects into NSArray - objective-c

Question

Trying to parse this JSON object in objective-C and creating an NSArray with these objects.
The first value is a counter and is specific for the object. All other values are unique.
{ "myData": [
["1","1","110","dollar","8.0","2.8","0.1","11.6"],
["2","1","110","euro","4.0","3.2","1.5","4.4"],
["3","1","120","rupier","6.0","2.9","1.3","10.8"],
["4","1","120","dinero","4.0","3.3","1.5","4.4"],
["5","2","130","drahmer","8.0","2.9","1.3","11.2"],
] }
Tried this code:
NSDictionary* json = [NSJSONSerialization
JSONObjectWithData:myData
options:kNilOptions
error:&error];
NSArray *currencyInformation = [json objectForKey:#"myData"];
But the objects are not there. Though the count of the array is 5.

Answer 1

Each object in the array is an array itself, so:
NSDictionary* json = [NSJSONSerialization
JSONObjectWithData:myData
options:kNilOptions
error:&error];
NSArray *currencyInformation = [json objectForKey:#"myData"];
for (NSArray *info in currencyInformation) {
// Then access each "column" with [info objectAtIndex:0,1,2,3,...]
}

Answer 2

In this data structure you would need to access things by index e.g
for (NSArray *currency in currencyInformation) {
NSLog(#"Currency: %#", [currency objectAtIndex:3]);
}
If you want to access things by key then you would need to change your JSON to use an array of objects instead of an array of arrays. Something like this:
{
"myData": [
{
"primaryKey" : 1,
"currency" : "dollar",
<other keys + values>...
},
]
}
In which case you could now do something like:
for (NSDictionary *currency in currencyInformation) {
NSLog(#"Currency: %#", [currency valueForKey:#"currency"]);
}