> In other words, is it ok to assume that the visitors most recent browser update is not earlier than september 2016?
const there’s https://caniuse.com/#search=const
It looks like
const is widely supported by browsers other than IE10 and before. However, it seems to be little gotchas (and potential issues) with many of them if you rely on what makes const great: block scope. If your concern is performance, I’d suggest that you should be fine using
var as browsers are good at optimizing code.
Thank you. I will stick to
var, just to be safe, and believing you with respect to browsers being good at optimizing code.