> map() is passing not only the value in the array but also its index as well as a copy of the full array. I use map() all the time but I didn't know about that

> map() is passing not only the value in the array but also its index as well as a copy of the full array. I use map() all the time but I didn't know about that until I read this article Then you don't know the basics of the language you're using- how can you complain about it? > when I use map() I expect it to take each value in the array and pass it to the callback function. I don't expect... map is well documented. Making the element's index available is indeed pretty useful (the entire array less so, but sometimes it can be).