Const-Let

Question 1

What is a code block? What are some examples of a code block?

Answer 1

a pair of braces ( {…} ) used to group multiple statements together,
ex.
if else, for, do, while, try catch

Question 2

What does block scope mean?

Answer 2

Declaring a variable inside and outside a block and having different values returned

Question 3

What is the scope of a variable declared with const or let?

Answer 3

const keyword are blocked-scope and cannot be redeclared
let keyword are block-scoped, are not initialized to any value, and are not attached to the global object.

Question 4

What is the difference between let and const?

Answer 4

const keyword creates a read-only reference to a value.
let keyword starts from the block until the initialization is evaluated

Question 5

Why is it possible to .push() a new value into a const variable that points to an Array?

Answer 5

because we are not redeclaring the variable we are just adding to the list

Question 6

How should you decide on which type of declaration to use?

Answer 6

use var if you want to reassign the value outside of a block
use let if you want to keep the same value outside block but inside block a different value
use const if you want to keep an immutable variable but can still change objects and array naturally