More Questions: Use Destructuring Assignment to Assign Variables from Arrays

JavaScript
#1

Why does adding const to [a, b] will make the command local?

Your code so far


let a = 8, b = 6;
(() => {
  "use strict";
  // change code below this line
  [a, b] = [6,8];
  // change code above this line
})();
console.log(a); // should be 6
console.log(b); // should be 8

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Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/es6/use-destructuring-assignment-to-assign-variables-from-arrays

#2

because const is block scoped, as you are in a function if you do that, the a and b variables are not changed but new variables with the same name but restricted to the local scope are created

#3