Intro And NPM

Question 1

Two things to do to run a server ?

Answer 1

1. Create a server
2. Start a server

Question 2

Http.createServer accepts what ?

Answer 2

A call back function with req and response options

Question 3

What is the standard IP address of the local host ?

Answer 3

127.0.0.1

Question 4

How can we see what options req method has ?

Answer 4

We can console log req parameter when we are creating a server. And we first create a server which takes a call back function this is where we can send back a response. And then we run the server by running listen method and this takes a couple of parameters like port number, host address and a call back function which you can use to console log server is running

Question 5

What module do we use in default node to set up routing ?

Answer 5

We use url module

Question 6

How do we implement the routing using http module ?

Answer 6

We save the req.url to a variable and then use a big if else statement to define routes for different requests

Question 7

Where do we assign a variable to req.url and where do we use if else statements to implement routing ?

Answer 7

If the the create server call back function

Question 8

How do you set a http status code ? Like 404

Answer 8

In the pure NodeJS example, you can use res.writeHead() method to send back a response. It will look like this
res.writeHead(404)

Question 9

How do you set content type in the header ?

Answer 9

You can send it with res.writeaHead(404, {
‘content-type’:’text/html/})
Content type is written as the second parameter in writeHead()

Question 10

How do you write Jason code ?

Answer 10

Both key value pairs should be strings separated by : inside curly bases. Json looks a lot like objects

Question 11

Give an example of receiving data in a Json file and then reading it. In this case console log it.

Answer 11

fs.readFile(‘./dev/text.txt’, ‘utf-8’, (err, data) =>{
const productData = JSON.parsedata(data)
console.log(productData)})

Question 12

How do you know which code will be executed once only ?

Answer 12

All the top level code gets executed once only

Question 13

When to use the sync version ? In this case give an example of fs.readFileSync

Answer 13

Whenever the code is supposed to be used once is when we can use sync version because sync version only gets executed once and same goes for the top level code.

Question 14

Give an example of adding place holders in HTML file

Answer 14

<h1>{%PRODUCTNAME%}<h1></h1>
</h1>

Question 15

When does readFileSync return a buffer ?

Answer 15

It returns a buffer when you don’t specify an encoding

Question 16

Most popular array methods ?

Answer 16

MAP, Filter and Reduce

Question 17

Describe three key characteristics of the map function

Answer 17

1. It runs a function on every element of an array
2. It does not executed a function on elements without values
3. The JavaScript map method does not change the original array

Question 18

When to use Map method ?

Answer 18

It is required whenever we went to call a function for every element of an array

Question 19

What happens if you don’t have curly braces in an arrow function ?

Answer 19

The function returns immediately.

Question 20

How do we define prettier configuration ?

Answer 20

We can create a file . prettierrc