Do I have to initialize every level of an object in Javascript?

I'm not terribly good with Javascript so I'm wondering if there is a better way of doing this:

if (games[level] === undefined) {
    games[level] = {};
    games[level]['pending'] = {};
}

if (!games[level]['pending'].length) {
    return game.create(level);
}

In PHP I can just test empty($games[$level]['pending']). Is there a better way of testing for this? Basically all I want to do is create the object if 开发者_StackOverflowit does not exist.

if (games[level] === undefined) {
    games[level] = game.create(level);
}

If there is no such level game create should be called to initialize all of the data needed. I don`t see any point of making it an object and then checking for "pending". It will be always empty, because you just created the object.

If your the second if returns something for games[level]['pending'].length you have a big problem with your code. You can`t create an empty object ( games[level]['pending'] = {} ) and find that it already has properties.

In addition:

games[level] = {};
// games[level]['pending'] = {}; - bad
games[level].pending = {}; // this way object properties should be used

you can make yourself a function to do that, pass it the games object a a string like "level.pending.id.something.something" and goes on and creates the objects.

function makeObj(obj, path) {
    var parts = path.split("."), tmp = obj, name;
    while (parts.length) { 
        name = parts.shift();
        if (typeof tmp[name] === 'undefined') {
              tmp[name] = {};
        }
        tmp = tmp[name];
    }
}

var x = {};
makeObj(x, "this.is.a.test");

games[level] = games[level] || {pending: {}};

if (!games[level].pending.length) {
    return game.create(level);
}