ES6 Const & Let

Question 1

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

Answer 1

A block of code within curly braces { };

Examples: if else, for, do while, while; function code block;

Question 2

What does block scope mean?

Answer 2

An area within the block where variables can be referenced

Question 3

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

Answer 3

Let = block-scoped;
Const = block-scoped

Question 4

What is the difference between let and const?

Answer 4

Const can’t be reassigned while let can.

Question 5

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

Answer 5

The value within the array is mutable

Question 6

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

Answer 6

If the variable is not going to be reassigned, use ‘const’. If it will be reassigned, then use ‘let’