[aaronm67]

In Underscore, you can do something like:

    _([ ... ]).map( ... ).filter( ... ).value()

It's not exactly extending the native array...but there are far fewer side effects to doing it this way.

[WickyNilliams]

The problem with this is that it's doing multiple iterations. LINQ on the other hand builds up an expression tree that is "compiled" into a single loop when `ToList()` (or some other method which gets the results) is eventually called.