Question

I’m trying to reference a Twitter username using Json and ObjectForKey

Example twitter JSON

source = web;
user =         {
        "contributors_enabled" = 0;
        "created_at" = "Tue Mar 09 11:36:02 +0000 2010";
        "default_profile" = 0;
        "default_profile_image" = 0;
        description = "Welcome to the Official Twitter page for Tottenham Hotspur Football Club, where you can get your official Club news, competitions and more!";
        "favourites_count" = 97;
        "follow_request_sent" = "<null>";
        "followers_count" = 360893;
        following = 1;
        "friends_count" = 80;
        "geo_enabled" = 0;
        id = 121402638;
        "id_str" = 121402638;
        "is_translator" = 0;
        lang = en;
        "listed_count" = 3514;
        location = "Tottenham, London, England";
        name = "Tottenham Hotspur";
}

Now I want to use the key name within user but have no clue how to reference it. I know if I wanted to use the source I could use

objectForKey:@"source"

but do not know what to put down for user:name

Answer 1

For the sake of education, an alternative would be to use the key-value coding mechanisms exposed via valueForKeyPath:.

Per the key-value coding fundamentals, valueForKeyPath: breaks down the supplied path by separating full stops and calls valueForKey: progressively on each member. So, e.g. the following are equivalent:

[obj valueForKeyPath:@"ted.jefferson"]
[[obj valueForKey:@"ted"] valueForKey:@"jefferson"]

Furthermore, NSDictionary implements its valueForKey: directly to call objectForKey: unless you’ve added an @ to access metadata rather than content. So in this case it is safe to substitute the one for the other, given that you’re using string keys.

Therefore the most abbreviated way to do what you want is:

[obj valueForKeyPath:@"user.name"]