ES6 variables

So, recently, I was doing a code review and found a piece of code which is like below



As you can see in the above code, The empty array that is defined as const is mutable. This is because - the constant constraint is enforced only on the variable type and not inside it.

This is the same with objects as well. You can see the example below

Scope is an important aspect in programming. This scope concept is quite different and challenging in JavaScript. This is more in case of variables because of the variable hosting concept.

Keyword - 'var' makes variables available at global if its not bound inside a function and when inside a function, it is available as a scope variable all throughout that function.

On the other hand, 'let' keyword restricts the variable similar to how the scope of variables in with C# or Java. This brings in the most needed advantage and functionality that has been making developers get nightmares for because of variable hoisting.