ES6

Question 1

Features of ES6

Answer 1

• arrow functions
• let/const
• template literals
• Classes
• destructuring
• Async & await

Question 2

Let/Const scope

Answer 2

Block scope = local scope

Question 3

Answer 3

Question 4

Arrow functions allows a ____ for writing function expressions.

Answer 4

short syntax

Question 5

Answer 5

Question 6

Arrow functions do not have their own ___. They are not well suited for defining object methods.

Answer 6

this

Question 7

Arrow functions are not ___. They must be defined before they are used.

Answer 7

hoisted

Question 8

You can only omit the ___ keyword and the curly brackets if the function is a single statement. Because of this, it might be a good habit to always keep them:

Answer 8

return

Question 9

JavaScript Classes are __ for JavaScript Objects.

Answer 9

templates

Question 10

Make a class Car with name property

Answer 10

Question 11

When you have a class, you can use the class to create objects:

For example create myCar2 using class Car

Answer 11

let myCar2 = new Car(“Audi”, 2019);

Question 12

___ are a cleaner and more beautiful way to play with strings.

Answer 12

Template literals

Question 13

They get rid of the need for a lot of + signs to concat strings.

Answer 13

Template literals

Question 14

Destructuring Objects: get firstName and lastName using it

let information = { firstName: 'Dylan', lastName: 'Israel'};

Answer 14

let { firstName, lastName } = information;

Question 15

Destructuring Arrays

Point to first element of the array with firstname

['Dylan', 'Israel'];

Answer 15

let [firstName] = ['Dylan', 'Israel'];

Question 16

____ allow you to omit the key in the object if the name of the key and value are the same.

Answer 16

object literal

Question 17

let firstName = 'Dylan';

// avoid key this is an example of:

let information = { firstName };

Answer 17

Object literal

So, in the example above, we wanted to add the property of firstName in our information object. The firstName variable is another variable with the same name. We omit the key and just pass the name of the variable, and it will create the property and assign value itself.

Question 18

, which creates a loop that iterates over iterable objects like String, Array, NodeList objects,

Answer 18

for .. of

Question 19

let str = 'hello';

Please use the new loop

Answer 19

for (let char of str) { console.log(char);}

// "h"// "e"// "l"// "l"// "o"

Question 20

Name of this functionality

Answer 20

Spread operator

The code above demonstrates one of the many cool implementations of using the spread operator. Here we are combining two arrays by putting them in a new array with three dots (…) in front of the name of the array.

Question 21

___ helps us handle function parameters in a better way by allowing us to represent the variable number of the function parameters as an array.

Answer 21

rest operator

Question 22

Here, we are calling the same function with a different number of parameters, and the ____ operator is handling that perfectly for us.

Answer 22

rest operator

Question 23

Using the ___ method, we can find out if any string contains a particular character or a substring. In this lesson, you will learn in detail about the practical use-cases of this function.

Answer 23

includes

Question 24

We all know how important it is to have modular code, especially if you are working on large-scale applications. With ___ and ___ statements in JavaScript, it has become extremely easy and clean to declare and use modules.

Answer 24

import and export

Question 25

// exports function

export function double(num) { return num * num; }

In the code above, we are exporting a function by the name of double. We’re then importing the function in a separate file

Answer 25

// imports function

import { double } from '..filepath/filename

Question 26

ES2017 introduced two new methods to manipulate strings, which you will learn in detail in this part. ___ and __ will simply add padding at the start and end of the string.

Answer 26

padStart and padEnd

Question 27

With ___, we can write asynchronous code which looks like synchronous code.

Answer 27

Async & Await

Question 28

Promises

Answer 28

a promise represents something async, it can be avaible now, in the future or never.

Question 29

a promise function has two arguments

Answer 29

resolve and reject

Question 30

sintax of promise

Answer 30

Question 31

Explain the promise

Answer 31

Explain the promise