Scoping rules The main difference is scoping rules. Variables declared by var keyword are scoped to the immediate function body (hence the function scope) while let variables are scoped to the immediate enclosing block denoted by { } (hence the block scope).
As the others have said, you can use var at global scope (outside of all functions and modules) to declare a global variable: (Note that that’s only true at global scope. If that code were in a module — <script type=”module”>…</script> — it wouldn’t be at global scope, so that wouldn’t create a global.) Alternatively: In modern … Read more
You can use a global variable within other functions by declaring it as global within each function that assigns a value to it: I imagine the reason for it is that, since global variables are so dangerous, Python wants to make sure that you really know that’s what you’re playing with by explicitly requiring the … Read more