Introduction

Question 1

What does console.log() ?

Answer 1

Data is printed, or logged, to the console, a panel that displays messages

Question 2

How do you comment one line?

Answer 2

We can write single-line comments with//

Question 3

How do you comment more than one line?

Answer 3

We can write multi-line comments between/*and/

Question 4

What are the 7 fundamental data types in JavaScript ?

Answer 4

Strings, numbers, booleans, null, undefined, symbol, and object.

Question 5

What is a string ?

Answer 5

Strings are characters wrapped in single or double quotes:’Sample String’

Question 6

What are the built-in arithmetic operators ?

Answer 6

The built-in arithmetic operators include+,,,/, and%

Question 7

What are the two things that objects can have ?

Answer 7

Properties & Method

Question 8

What is a method?

Answer 8

Methodsare actions we can perform. Data types have access to specific methods that allow us to handle instances of that data type.

Question 9

How do you call(or use) a method?

Answer 9

With :
- a period (the dot operator)
- the name of the method
- opening and closing parentheses

E.g.'example string'.methodName().

Question 10

How is denoted a property on an object ?

Answer 10

The properties are denoted with a.after the name of the object, for example:’Hello’.length.

Question 11

What is the data type object ?

Answer 11

Collections of related data.

Question 12

What is the data type symbol ?

Answer 12

A newer feature to the language, symbols are unique identifiers, useful in more complex coding. No need to worry about these for now.

Question 13

What is the data type undefined?

Answer 13

This data type is denoted by the keywordundefined(without quotes). It also represents the absence of a value though it has a different use thannull.undefinedmeans that a given value does not exist.

Question 14

What is the data type Null?

Answer 14

Null: This data type represents the intentional absence of a value, and is represented by the keywordnull(without quotes).

Question 15

What is the data type Boolean?

Answer 15

Boolean: This data type only has two possible values— eithertrueorfalse(without quotes). It’s helpful to think of booleans as on and off switches or as the answers to a “yes” or “no” question.

Question 16

What is the data type string ?

Answer 16

Any grouping of characters on your keyboard (letters, numbers, spaces, symbols, etc.) surrounded by single quotes:’ … ‘or double quotes” … “, though we prefer single quotes. Some people like to think of string as a fancy word for text.

Question 17

What is the data type number ?

Answer 17

Any number, including numbers with decimals:4,8,1516,23.42.

Question 18

What is the definition of Data types?

Answer 18

Data typesare the classifications we give to the different kinds of data that we use in programming. In JavaScript, there are seven fundamental data types

Question 19

What are the 6 of data type consideredlike primitive data types?

Answer 19

Strings, numbers, booleans, null, undefined and symbol

Question 20

Which data type is not considered like a primitive date type?

Answer 20

Objectsare more complex, and you’ll learn much more about them as you progress through JavaScript. At first, seven types may not seem like that many, but soon you’ll observe the world opens with possibilities once you start leveraging each one. As you learn more about objects, you’ll be able to create complex collections of data.

Question 21

What “.toUpperCase()”method is going to do to a string?

Answer 21

This method returns a string in all capital letters

Question 22

What “.startsWith()” method is going to do to a string ?

Answer 22

This method also accepts the character’H’as an input, orargument, between the parentheses. Since the string’Hey’does start with the letter’H’, the method returns the booleantrue.

Question 23

What are Built-in objects ?

Answer 23

Built-in objects, includingMath, are collections of methods and properties that JavaScript provides.

Question 24

What does Math.floor (built-in object) do?

Answer 24

Math.floor()rounds the number down to the nearest whole number.

Question 25

What does Math.random (built-in object) do?

Answer 25

Math.random()generates a random number between 0 and 1.

Question 26

What is it going to print ?
console.log(Math.floor(Math.random() *50));

Answer 26

Prints arandom whole number between 0and 50
1. Math.random()generates a random number between 0 and 1.
2. We then multiply that number by50, so now we have a number between 0 and 50.
3. Then,Math.floor()rounds the number down to the nearest whole number.

Question 27

Properties

Answer 27

When you introduce a new piece of data into a JavaScript program, the browser saves it as an instance of the data type. All data types have access to specific properties that are passed down to each instance. For example, every string instance has a property calledlengththat stores the number of characters in that string.