Decode JSON to NSArray or NSDictionary

Question

I hope to decode the JSON data below:

{
    "content":
    [   
        {
            "1":"a",
            "2":"b",
            "3":"c",
            "4":"d",
            "mark":"yes"
        }
    ]
}

Not sure if put it in NSArray or NSDictionary

Welcome any comment

Answer 1

which iOS version are you using? in iOS 5 you have the NSJSONSerialization class to parse JSON data, if you need to target older iOSs or MAC OSX you should use third parties lib such as SBJSON. The string posted will be a NSDictionary with an array with one dictionary. The array will be accessible using the key @"content"

In code:

NSString * jsonString = @"blblblblblb";
NSStringEncoding  encoding;
NSData * jsonData = [jsonString dataUsingEncoding:encoding];
NSError * error=nil;
NSDictionary * parsedData = [NSJSONSerialization JSONObjectWithData:jsonData options:kNilOptions error:&error];

In SWIFT 2.0:

    let jsonString = "blblblblblb"
    let encoding = NSUTF8StringEncoding
    let jsonData = jsonString.dataUsingEncoding(encoding)
    guard let jData = jsonData else {return}
    do {
        let parsedData = try NSJSONSerialization.JSONObjectWithData(jData, options: [])
    } catch let error {
        print("json error: \(error)")
    }

[UPDATE] The NSJSONSerialization class is also available for 10.7 my comment wasn't correct.

Answer 2

That particular string will decode into an NSDictionary because the outermost thing is a JSON object which maps onto a NSDictionary for every JSON implementation I have ever seen. If you want to process an arbitrary string, you'll need to test what you get back

NSError *jsonError;
id parsedThing = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonError];
if (parsedThing == nil)
{
    // error
}
else if ([parsedThing isKindOfClass: [NSArray class]])
{
    // handle array, parsedThing can be cast as an NSArray safely
}
else
{
    // handle dictionary, parsedThing can be cast as an NSDictionary
    // NB only dictionaries and arrays allowed as long as NSJSONReadingAllowFragments 
    // not specified in the options
}