[ryanlm]

Yesterday I had to store integers as keys in a map. It's good to learn today that they are implicitly converted to strings. Yes I could have used an array, but that would of required me to know the max index I would suppose. Maybe in JavaScript I insert into the array at any index, but that doesn't seem usual to me, coming from a C background I'd allocate the max index + 1.

[chrisseaton]

I'm not a JavaScript expert but I believe most serious JavaScript implementations can represent sparse arrays, or arrays with holes in the range of indices, for this reason.

[BillinghamJ]

Vaguely relevant/example: http://imgur.com/7Bf3hLZ

[fenomas]

If performance is important, I believe it's still a fair bit faster to use a plain object as hash, rather than a Map. (If the keys are integers V8 may initially treat the object as an array, but it'll switch over to dictionary mode pretty quickly.)

[rasz_pl]

just be glad it didnt store random integers as floats (happened to me when storing integer timestamps into webstorage)