Can you use const in a classic for loop in JavaScript?

Because let creates a fresh binding of the loop variable per iteration. Each callback closes over its own copy of i, which holds the value for that iteration. With var, all callbacks share one i, which is the final value by the time they run.

Yes. Each iteration of for...of creates a fresh binding, and the loop variable does not change within an iteration. const is appropriate and preferred for for...of and for...in.

With an IIFE (immediately invoked function expression) that captured the current value of i as a parameter. Each iteration created a new function scope, so each callback closed over its own copy.