Recursively sort object keys

gistfile1.js

var _ = require('underscore');

function sortObject(obj){
    var oNew = {};
    if(typeof obj === 'object'){
        var aKeys = _.keys(obj);
        aKeys.sort();
        _.each(aKeys, function(sKey, oVal){
            oNew[sKey] = sortObject(obj[sKey]);
        });
    } else {
        return obj;
    };

    return oNew;
}

var a = {
    z : 123,
    b : 1,
    g : 2,
    c: {
        l:1,
        a:2
    }
}

a = sortObject(a);
console.log(a);