Javascript

Question 1

How would you create a .js file named Digital Nomad from the terminal?

Answer 1

touch digital-nomad.js

Question 2

How would you run a js file named digital-nomad.js from the terminal?

Answer 2

node digital-nomad.js

Question 3

What is the difference between shell REPL and the node REPL?

Answer 3

The shell REPL executes system commands, while the node REPL executes JavaScript. You can’t use the shell to execute JavaScript, and you can’t use node to execute system commands.

Question 4

How would you write a comment in Javascript code?

Answer 4

// Comment goes here

Question 5

What are two ways we would name a constant in JavaScript?

Answer 5

CamelCase (PascalCase) or ALL_CAPS_LIKE_THIS

Question 6

In JavaScript, there are seven fundamental data types: what are they?

Answer 6

Number, String, Boolean, Null, Undefined, Symbol, Object

Question 7

Explain the Number Datatype:

Answer 7

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

Question 8

Explain the String Datatype:

Answer 8

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 9

Explain the Boolean Datatype:

Answer 9

This data type only has two possible values— either true or false (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 10

Explain the Null Datatype:

Answer 10

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

Question 11

Explain the Undefined Datatype:

Answer 11

This data type is denoted by the keyword undefined (without quotes). It also represents the absence of a value though it has a different use than null.

Question 12

Explain the Symbol Datatype:

Answer 12

A newer feature to the language, symbols are unique identifiers, useful in more complex coding.

Question 13

Explain the Object Datatype:

Answer 13

Collections of related data.

Question 14

What is a method? & Give an example

Answer 14

A Method is an action we can perform. Example: E.g. ‘example string’.methodName().

Question 15

Say you have this variable let nomad = ‘Digital Nomad’; How would you do string interpolation.

Answer 15

console.log(My name is Daniel and I am a ${nomad}) we have to use backticks

Question 16

Dog Years

Dogs mature at a faster rate than human beings. We often say a dog’s age can be calculated in “dog years” to account for their growth compared to a human of the same age. In some ways we could say, time moves quickly for dogs — 8 years in a human’s life equates to 45 years in a dog’s life. How old would you be if you were a dog?

Here’s how you convert your age from “human years” to “dog years”:

The first two years of a dog’s life count as 10.5 dog years each.
Each year following equates to 4 dog years.
Before you start doing the math in your head, let a computer take care of it! With your knowledge of math operators and variables, use JavaScript to convert your human age into dog years.

If you get stuck during this project or would like to see an experienced developer work through it, click “Get Unstuck“ to see a project walkthrough video.

Code the following in a code editor and create the file in ‘projects’ on your comp via the terminal and push it to git.

Answer 16

const myAge = 29; // My current age 
let earlyYears = 2; 
earlyYears *= 10.5 
let laterYears = myAge - 2;
laterYears *= 4;
let myAgeInDogYears = earlyYears + laterYears;
let myName = 'DANIEL'.toLowerCase();
console.log(`My name is ${myName}. I am ${myAge} years old in human years which is ${myAgeInDogYears} years old in dog years`);