Error (undefined variable) in jQuery

Why is that JSON feed returning an undefined variables while working for other variable? What am I doing wrong or overlooking? Thanks开发者_JAVA技巧.

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If you take a look at the contents in response:

curl http://gdata.youtube.com/feeds/users/kaycor/favorites?alt=json-in-script&callback=mycallback

You see that entry.media$group and entry.yt$statistics are not there:

gdata.io.handleScriptLoaded({
    "feed": {
        // snip ...
        "entry": [{
            // snip ...
            "media$group": {
                "media$category": [{
                    // snip ...
                }],
                "media$title": {
                    // snip ...
                }
            }
        }]
    }
});

Edit: Not all items contain the media$content array, so you should modify your each block to something like this:

$.each(data.feed.entry, function(i, item){
    var uploader = item['author'][0]['name']['$t'];
    if (item['media$group']['media$content']) {
        var URL = item['media$group']['media$content'][0]['url'];
        var thum = item['media$group']['media$thumbnail'][0]['url'];
    }
});

I wrote a quick test script for this and with the if clause in place, it did not throw errors anymore.