ES6

Question 1

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

Answer 1

code that is grouped together and goes together

Functions have a code block of what they will do when called

Question 2

What does block scope mean?

Answer 2

code only available in the code block it is declared

Question 3

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

Answer 3

const is a read only reference to a value (as in your not supposed to change the value) and you can not reassign the value
let lets you declare a block scope variable
neither const or let are window objects

Question 4

What is the difference between let and const?

Answer 4

let you can change the value of what it is set to and const you cant

Question 5

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

Answer 5

const only prevents you from reassigning the value not from adding or deleting properties
const only holds a pointer value

Question 6

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

Answer 6

if you plan on changing the variable to soot your needs then use let but if its going to be the same use const

Question 7

What is the syntax for writing a template literal?

Answer 7

Instead of single or double quotes you use backticks

Question 8

What is “string interpolation”?

Answer 8

the ability to substitute part of the string for the values of variables or expressions

Question 9

What is destructuring, conceptually?

Answer 9

simpler way of taking properties out of objects or arrays

Question 10

What is the syntax for Object destructuring?

Answer 10

instead of variable name its {property name}

Question 11

What is the syntax for Array destructuring?

Answer 11

instead of variable name its [name you want in the index you want]

Question 12

How can you tell the difference between destructuring and creating Object/Array literals?

Answer 12

destructuring doesnt change the original array/object

Question 13

What is the syntax for defining an arrow function?

Answer 13

()=>{}

Question 14

When an arrow function’s body is left without curly braces, what changes in its functionality?

Answer 14

only the first expression is returned as in implied return

Question 15

How is the value of this determined within an arrow function?

Answer 15

an arrow function captures the this value of the enclosing context instead of creating its own this context / arrow functions have a lexical scope and take on whatever it is in