This answer is what the kata asked for, not the top voted solution. I think this should be top voted.

It's a brillant solution.

I always forget to inline and return the index I want all together. This makes it much cleaner. 👍

This is N Log N time complexity. This task can be completed in N.

array_keys has a search_value parameter my life is changed

Oh! Now I see it! The starting code was with a constructor function so I assumed this problem was also with one. My bad, next time I should double check ;)

This code does create a method on the prototype. It does not create a separate function for every Ship instance. Test it for yourself if you don't believe me :)

It's better to attach the function on the prototype : Ship.prototype.isWorthIt = function(){ ... } because you create the function once and every instance of the Ship constructor can use it while in your code you create a separate function for every instance :)

again interesting solution

five years working with php and didn't know about this function... wtf was I doing?

Can't believe I did a nested loop for this! ^-^