Answer by Danny R for Iterate through object properties

As of JavaScript 1.8.5 you can use Object.keys(obj) to get an Array of properties defined on the object itself (the ones that return true for obj.hasOwnProperty(key)).

Object.keys(obj).forEach(function(key,index) {
    // key: the name of the object key
    // index: the ordinal position of the key within the object 
});

This is better (and more readable) than using a for-in loop.

Its supported on these browsers:

• Firefox (Gecko): 4 (2.0)
• Chrome: 5
• Internet Explorer: 9

See the Mozilla Developer Network Object.keys()'s reference for futher information.