No, I meant "expected by anyone who learned the language". Knowing the addition operator including its limitations is quite basic. I'm not saying you need to be

No, I meant "expected by anyone who learned the language". Knowing the addition operator including its limitations is quite basic. I'm not saying you need to be able to solve all this "JavaScript is weird" puzzles as they are mostly non-sense. But you definetely have to know what you can us `+` for. If someone does not like the ECMAScript specification, that is fine. But at least use a proper unofficial documentation like MDN.