Logging Global variable inside the function Block immediately before redeclaration going undefined: Should not it take the Global Variable Value?

Question

let pages =100;
let pageFunction=()=>{
 console.log(pages);
 const pages = "20";
 //console.log(pages);
}
pageFunction();

Output: Uncaught ReferenceError: pages is not defined at pageF (:3:13) at :1:1

Variable declarations apply to the whole scope, even if execution hasn't reached them yet. — loganfsmyth, Mar 17 '17 at 05:15

score 1 · Answer 1 · answered Mar 17 '17 at 05:21

According to Mozilla "The let statement declares a block scope local variable, optionally initializing it to a value." Also "At the top level of programs and functions, let, unlike var, does not create a property on the global object."

See https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Statements/let for more information.

This means that in the code you gave you effectively create an implicit global variable pages, as let pages is not really global, but restricted to the scope it is in.

Logging Global variable inside the function Block immediately before redeclaration going undefined: Should not it take the Global Variable Value?

1 Answers1