A JavaScript Optional Argument HazardMy recent post on testing for negative 0 in JavaScript created a lot of interest. So today, I’m going to talk about another bit of JavaScript obscurity that was also inspired by a Twitter thread. I recently noticed this tweet go by: This was obviously a trick question. Presumably some programmer expected this expression to produce an array like [1, 2, 3] and it doesn’t. Why not? What does it act
