Oh wow, this is a great solution.

Any chance you'll explain your solution?

There is (unless it was just added recently), but it had null as o1 and undefined as o2, so the third line of your code (typeof o2 !== 'object') returned false.

Certainly true.

Then there should be a test for that, right? :-)

This doesn't work for:

deepCompare({name: 'blah'}, null);

typeoff null returns 'object', so it will pass the third line, next Object.keys(null) will throw an error.

Thanks ! It is a very useful function :)

In my opinion it is not just preference. At least not when you try to write code which most clearly conveys what it is supposed to do. In this case we want to know if every element in an array is an integer. Afterwards, it's just micro optimization I'd say. (I.e. if you have an every implementation that continues after the predicate returns false, than fix the implementation in stead of working around).

Excellent kata, totally uplives it's goal.

Aesthetic. Nothing more.