Const Redeclaration Javascript

Question

So i started learning Javascript a few weeks ago from an online course. I got up to a point where i started learning the DOM manipulation and there's an exercise to generate a random colours for the background. At first i saved the random colour to a let variable. But when i see the answer for the exercise, it uses a const not let. How is this possible, I thought const can't be redeclared?

 function randomColour() {
 const r = Math.floor(Math.random() * 255);
 const g = Math.floor(Math.random() * 255);
 const b = Math.floor(Math.random() * 255);
 return `rgb(${r},${g},${b}`;
 }

• Adam Jenkins: First, those variables are not being reassigned inside that scope, therefore const is fine. Second, in general, if you aren't going to change a variable later you should always use const and with you'll enforce this habit with linters. Third, using let instead of const is fine, your answer is correct, but see my second point.

Answer 1

Whenever the function gets called, there is a new environment record which stores all the variables declared in the function. A const variable can be stored only once. If you call the function again, there is a new record, and as such the variable can hold another value.

 function a() {
 const b = Math.random();
 // assigning b again here won't work
 }
 a(); 
 a(); // new record, new value