Use Destructuring Assignment to Assign Variables from Arrays: Problems with Hints

Tell us what’s happening:
The code below is correct but I don’t understand why the hint said: const [b,a] = [a,b] will result in the value of a,b as undefined(simple assignment rule left to right), while [a, b] = [b, a] is correct.
The other hint said: No need of const [b,a] as it will keep the effect of assignment local, what does it mean by local? aren’t the two variables swap values in the global scope?
Your code so far

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

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Challenge: Use Destructuring Assignment to Assign Variables from Arrays

Link to the challenge:

Both hints are incorrect

  1. If you try to use const you will get SyntaxError because you’ve already declared a and b in the first line
  2. [a, b] = [b, a] is absolutely the same as [b, a] = [a, b]