Right but we have `let` now which solves that problem.

Not completely, `let` also has a weird temporal dead zone[1], which is basically a dynamic check.

[1] https://www.freecodecamp.org/news/what-is-the-temporal-dead-...

That's a good thing, and I'm not sure what you mean about it being a dynamic check.

It's a dynamic error if you access a let-bound variable before it is actually initialized. In most other languages that have lexically-scoped declarations, it simply would not be visible. So I think JS's choice is actually a regression.

To be more specific the term is hoist which means the declarations are pushed to the top of the scope at run time for maximum availability, and var is function scoped instead of block scoped. Block scoping is often more specific because a function body is a block as well.

var is a terrible example of that. Just don't use it.

A good example would be the scoping in for loops and maybe arrow functions. For loops are goofy but virtually never an issue, and arrow functions are awesome.

They were referring to `let`