es6-const-let

Question 1

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

Answer 1

A code block is anything between curly braces. Functions, conditional blocks, or loops have their own code blocks.

Question 2

What does block scope mean?

Answer 2

Block scope means that a variable is declared and lives between the curly braces but does not live outside those set of curly braces.

Question 3

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

Answer 3

Block scope

Question 4

What is the difference between let and const?

Answer 4

Let is a variable declaration keyword for mutable variables and const is a variable declaration keyword for immutable variables.

Question 5

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

Answer 5

The contents of reference data types can change as long as there is no reassignment.

Question 6

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

Answer 6

Use const to declare variables unless the value has to be reassigned, then use let