es6-const-let-Q&A

Question 1

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

Answer 1

JavaScript statements can be grouped together in code blocks, inside curly brackets {…}. The purpose of code blocks is to define statements to be executed together.

Question 2

What does block scope mean?

Answer 2

Block scoped variables: A block scoped variable means that the variable defined within a block will not be accessible from outside the block.

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

Both the let and the const keyword are ways to declare block scoped variables. There is one big difference though: Variables declared with let can be reassigned. Variables declared with const have to be initialized when declared and can’t be reassigned.

Question 5

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

Answer 5

You can change the contents of the array but not change the actual value

Question 6

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

Answer 6

If the variable needs to change use let, otherwise use const