I have a JavaScript Object and I'm sure the value of any key is an array (even empty in some case):

```
{key1:["a","b","c"],key2:["d","e","f"],key3:...}

```

Aside from using Underscore, is there any way to concatenate all the values of this Object (and create a new array)?

At the moment I get the keys name using `Object.keys`, then I loop and concatenate.

Any help is appreciated.