In javascript, as per my understanding, we can declare variables with let and var keywords and assign it a value later.

var a;
a = 5;

But, when I try the same approach with const keyword it does not work.

const a;
Uncaught SyntaxError: Missing initializer in const declaration

I understand my question has a basic contradiction because const keywords are used for storing immutable variables. Therefore, a good coding practice may require it to be initialized while being declared.

However, I want to store global value in a const variable that is being fetched by an API. So, I was wondering if there is a way to assign a value to a pre-declared const variable in javascript?