es6

Question 1

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

Answer 1

a chunk of code contained by {}. Examples include function definition, if/else statements, for loops

Question 2

What does block scope mean?

Answer 2

block = code block. variables are not accessible outside of the block they were declared in

Question 3

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

Answer 3

the block where it was declared (block-scope)

Question 4

What is the difference between let and const?

Answer 4

const cannot be reassigned

Question 5

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

Answer 5

const variables can still be modified in certain ways, but they cannot be reassigned/redeclared

Question 6

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

Answer 6

depending on how it will be used

Question 7

What is the syntax for writing a template literal?

Answer 7

like a string but ${different}

Question 8

What is “string interpolation”?

Answer 8

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

Question 9

What is destructuring, conceptually?

Answer 9

Taking the values from an array/object and creating individual variables for them

Question 10

What is the syntax for Object destructuring?

Answer 10

let { property1: variable1, property2: variable2 } = object;

Question 11

What is the syntax for Array destructuring?

Answer 11

let [x, y, z] = array;

Question 12

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

Answer 12

look at what’s on which side of the =

Question 13

What is the syntax for defining an arrow function?

Answer 13

const doSomething = (parameter1, parameter2) => {
    code goes here;
}

Question 14

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

Answer 14

implicit return

Question 15

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

Answer 15

this is pulled from the enclosing context