Should avoid mutating input.

Clever, but not best practice.

1. Should not modify input
2. Should not splice array you are iterating over even though length is updated
3. Should not have two counters for the same iteration

Need more basic tests. Top voted solution does not test for basic cases such as "?1+1=2", "1+?1=2" and "1+1=?2". Both should evaluate to -1, but top solution evaluates to 0.

More random test cases couldn't hurt either.

Ignoring the lack of random tests (and only a few hardcoded tests), this is still not best practice or even that clever.

You don't need all those checks which make the code hard to read.

It is unfortunate that none of the top solutions use algebra to solve this, but all choose a brute force algorithm...

It is definitely a byproduct of the kata requiring the next highest pair for false results.

It is unfortunate that none of the top solutions use algebra to solve this, but all choose a brute force algorithm...

It is definitely a byproduct of the kata requiring the next highest pair even for false results.

It is unfortunate that you require the nearest pair or else there is an elegant algebraic solution.

Basically, it seems like you approached it algorithmically and got a nearest pair from your algorithm, so you just added it as a requirement for the return value.

JS needs random tests.

Not sure why everyone is writing so much code when there are no random tests on a 4 kyu.

Can literally solve the kata in less than a minute without even thinking about an algorithm...

Calling an object literal arr...

I wish there was a downvote feature...

Your solution loops through twice as well... What's the point of nitpicking time complexity when you are doing the same thing? Your else also doesn't need to find anything. You already have it in evenValues[0]. Even with that optimization, your worst case is still n^3 for an array length of 3 and n^2 for other cases.

At least come up with a performant solution without unnecessary things before complaining that other people's solutions are "unnecessary and not performant".