SSD ICT

Question 1

Aim of backend?

Answer 1

Lays the foundational code
that enables websites to process actions that users take on front-end
and deliver correct information in return.

Question 2

Purpose of backend

Answer 2

Handles the ‘behind-the-scenes’ functionality of web apps.
Manages user connections.
Powers the user interface of the web application.
Connects the web app to a dataase

Question 3

Roles of back-end developer

Answer 3

Writing APIs & libraries.
Working on business processes and data architecture.
Writing code to interact with a database.

Question 4

What does browser as host environment allow?

Answer 4

Capture of user’s input.
Making of HTTP requests.
Processing of JavaScript instructions to output HTML and CSS.

Question 5

What is node.js

Answer 5

Open-source, cross-platform, back-end JavaScript runtime environment

Node.js as host runtime environment gives JavaScript access to OS

Question 6

What does Node js allow js to do

Answer 6

• Be used as utility scripts to configure system and to read, write and manipulate files.
• Send and receive data over the network.
• Implement efficient web servers and attach application code to it.
• Make and serve HTTP requests.

Question 7

What are the features of node.js

Answer 7

Open-source, cross-platform, back-end JavaScript runtime environment.
Event-driven architecture capable of asynchronous I/O operations
* reading from the network, accessing a database, modifying a file, etc.
Fully platform independent: Windows, macOS and Linux.
Full support for both types of databases:
* Relational DBs - Mysql
* NoSQL DBs -MongoDB

Question 8

What is nodemon?

Answer 8

A package that automatically restarts the server if a change in the source code or file change in the directory is detected

Question 9

What is dotenv?

Answer 9

Module that loads configuration environment variable from separate .env file.

Question 10

What is express js?

Answer 10

Minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.

Question 11

Features of express js.

Answer 11

o It provides a robust set of features to develop web apps.
▪ It sets up handlers to respond to different HTTP requests.
▪ It performs different actions based on HTTP Method and URL
▪ It sets common web app settings such as connection port and template locations.
▪ Dynamically renders HTML Pages based on passing arguments to templates.

Question 12

What is nvm?

Answer 12

A tool to manage the node version.
* Switch between different Node versions.
* Quickly update your installation when new releases are available.

Question 13

What is npm?

Answer 13

• Package manager for JavaScript, default package manager for Node.js.
• Includes a registry i.e. an online catalogue of libraries, can be accessed via client
• Track what libraries your project is using (called dependencies)
• Download the packages they depend on (called subdependencies)
• Store versioning information.
• Distinguish between test and production builds.

Question 14

How does Node js enable js everywhere

Answer 14

This allowed JavaScript:
o to be uncoupled from browser and to run on the server, including on cloud-based servers.
o to use the same language both on the server and client.
o to be used as part of several front-end frameworks (e.g., React, Vue.js, Angular) and back-end
frameworks (e.g., Express.js, Next.js, Sails.js
o to be used as part of several stacks e.g., MEAN stack (MongoDB, Express, Angular, Node) and MERN
stack (MongoDB, Express, React, Node).

Question 15

When is node js most suitable?

Answer 15

For apps that require high scalability across multiple servers and DBMSs.

High perf apps with dynamic single-page applications (SPAs) that work in a data-intensive &
real-time manner, including distributed sessions across multiple devices.

Question 16

Node js capabilities

Answer 16

Build software tools
Web scraping and testing
Build desktop applications
Build mobile applications
Build smartphone or tablet apps
Internet of Things (IoT)

Question 17

What is Ejs?

Answer 17

o One of the most popular template engines for JavaScript.
o It enables to rapidly build web applications that are split into different components.
o It embeds JavaScript code in a reusable web template to generate HTML.
o It replaces the variables in a template file with actual values and displays this value to the client.
o It retains the syntax of HTML while allowing data interpolation.

Question 18

What is a web template engine?

Answer 18

Software that combines web templates with a data source to generate
HTML by replacing variables in a template file with actual values.
data source - json, xml
web template - reusable template created using templating language
templating language - javascript java asp

Question 19

What is Mongoose?

Answer 19

Object Data Modelling (ODM) library for MongoDB and Node.js.
It acts as a front-end to MongoDB
* MongoDB: document-oriented NoSQL database, stores data in BSON.

Question 20

Advantages of nosql databases

Answer 20

Scalability - able to meet the needs for varying data loads.

Question 21

What is a JSON document?

Answer 21

o Documents consist of name-value pairs.
o Names are strings.
o Values can be numbers, strings, nulls, arrays, or objects

Question 22

What is a collection?

Answer 22

Gathering of documents.
Like a table in relational DB.
No need to specify a schema
Can change structure of docs in a collection.

Question 23

Benefits of using mongodb as a DBaas

Answer 23

Cost savings - cost based on usage
Cheaper management - db management done by cloud provider, no need staff
Data Security - done by cloud service provider
Scalability - up/down based on requirements

Question 24

What are environmental variables?

Answer 24

Variables that are set outside source code, often through a cloud provider or an Operating System
Supported by node and accessible via dotenv module.
Used to securely configure elements that dont change often. Like DB connection strings