what is function scoped variables (var) and block scoped variables in es6?

Question

I am new to javascipt as I have started learning js now, I am pretty confused with var that is said to be function scoped and block scoped;

If so then how do we access them outside of that function!? lets say i want to use it from another class (I don't know maybe by creating some object or whatever) (I guess we can't create objects here! because as it is a functional programming based language I guess!:( )

var y = "global";

if (y === "global") {
  var y = "block-scoped";
  console.log(y); // expected output: block-scoped
}

console.log(y); // expected output: block-scoped

The code logs as you expected. – Maheer Ali Mar 31 '19 at 18:34 — Maheer Ali, Mar 31 '19 at 18:34
yes but i had some other doubts and it cleared now! – Imran S M Mar 31 '19 at 18:51 — Imran S M, Mar 31 '19 at 18:51

Scott Marcus · Accepted Answer · 2019-03-31T18:56:56.557

var is not said to be function scoped.

Variables declared with var can either be function or Global scoped.

If the declaration occurs within a function, then the variable is scoped to that function.
If the declaration occurs outside of a function, then the variable is scoped Globally.

If a variable is declared with let or const, then it has block level scope. A block is delimited by {} or if those symbols are not present, the enclosing function or, if not in a block or a function, then Global.

I've written another post that discusses scope and the scope chain in much greater detail and should help in answering your coding scenario.

what is function scoped variables (var) and block scoped variables in es6?

1 Answers1