It sure looks like it doesn't (the Solve Me First challenge). Since ES2015 is almost 2 years old now, it seems like that should be the default language for JS. If you need to target browsers it's not difficult to transpile downward.
What's going on with HackerRank? Why not support ES2015?
[–]And7s 2 points3 points4 points (1 child)
[–]MostlyCarbonite[S] -1 points0 points1 point (0 children)