As many useful things as there are in ES2015 (and beyond!), it's probably worth pointing out a few "corporate" environmental constraints that might limit one to

As many useful things as there are in ES2015 (and beyond!), it's probably worth pointing out a few "corporate" environmental constraints that might limit one to ES 5.1: * IE11 isn't dead yet. MS still supports it. * The "Nashorn" engine inside (Oracle) Java 8 only supports 5.1. Scoff at them if you will, but some of us have to live with these things, and aren't using a transpiler.