How can I traverse this Javascript object?

Question

How can I traverse this Javascript object?

Possible Duplicate:
How do I enumerate the properties of a javascript object?

{ 
       347655082: {
                    album:{
                            title: "A",
                            genre: "Pop",
                          }
        },

        347655083: {

                    album:{
                            title: "B",
                            genre: "Rock", 
                          }
        }
}

Normally the "outside" key is the same, so I can easily target the nested objects. In the case the "outside" key is variable which can be anything.

albums = JSON.parse(json); //parse json storing it in albums

I cannot run a foreach on albums, say "albums has not method foreach".

albums.forEach(function(album, i){


}

javascript
json
node.js

Answer 1

You can only use .forEach() on arrays. Your albums entity is an Object so you should use for ... in ...)

for (var key in albums) {
    if (albums.hasOwnProperty(key)) {
        // do something with albums[key]
        ...
    }
}

For code targetting node.js or any other ES5 implementation you could probably omit the if clause - it's only needed if you've got code that has unsafely added stuff to Object.prototype.

Answer 2

ES5 has a great method for iteration object own enumerable properties - Object.keys(obj). I prefer the following iteration method:

Object.keys(albums).forEach(function (key) {
   console.log(albums[key]);
});

Answer 3

That's not valid json The valid json would be:-

    {
    "347655082": {
        "album": {
            "genre": "Pop", 
            "title": "A"
        }
    }, 
    "347655083": {
        "album": {
            "genre": "Rock", 
            "title": "B"
        }
    }
}

keys in json need to be double quoted as shown.

To validate json checkout jsonlint.com