I love node - it's a really irresponsible way of programming. The objective is to make as much the concern of someone else as possible. "How do I know what an array is? I'm just writing this app that works with arrays.."

:-)

In seriousness though, there many ways to write an isArray. Just yesterday I was looking at the different things String::repeat() handles on Mozilla's site. What seems trivial can be defined slightly differently everywhere and I tend to reach into the npm bag if I know it's open to interpretation.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...