Node

Question 1

What is Node.js?

Answer 1

Node.js is a program that allows JavaScript to be run outside of a web browser.

Question 2

What can Node.js be used for?

Answer 2

It is commonly used to build back ends for Web applications, command-line programs, or any kind of automation that developers wish to perform.

Question 3

What is a REPL?

Answer 3

A read–eval–print loop (REPL), also termed an interactive toplevel or language shell, is a simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user; a program written in a REPL environment is executed piecewise.

Chrome Dev Tools Console is one

Question 4

When was Node.js created?

Answer 4

May 2009

Question 5

What back end languages have you heard of?

Answer 5

Node, Python, PHP, Ruby

Question 6

What is a computer process?

Answer 6

In computing, a process is the instance of a computer program that is being executed by one or many threads. It contains the program code and its activity. Depending on the operating system (OS), a process may be made up of multiple threads of execution that execute instructions concurrently.

Question 7

Roughly how many computer processes are running on your host operating system (Task Manager or Activity Monitor)?

Answer 7

125

Question 8

Why should a full stack Web developer know that computer processes exist?

Answer 8

Because Full stack Web development is based on making multiple processes work together to form one application, so having at least a cursory awareness of computer processes is necessary.

This will be extremely important when learning about applications made of multiple components, such as clients, servers, and databases.

Question 9

What is the process object in a Node.js program?

Answer 9

The process object is a global that provides information about, and control over, the current Node.js process. As a global, it is always available to Node.js applications without using require().

Question 10

How do you access the process object in a Node.js program?

Answer 10

Just type process, it is always available Treat it like any other object.

Question 11

What is the data type of process.argv in Node.js?

Answer 11

Array

Question 12

What is a JavaScript module?

Answer 12

Module in Node. js is a simple or complex functionality organized in single or multiple JavaScript files which can be reused throughout the Node. js application.

A Module specifically refers to a file

Question 13

What values are passed into a Node.js module’s local scope?

Answer 13

exports, require, module, __filename, __dirname

Question 14

Give two examples of truly global variables in a Node.js program.

Answer 14

Console, process, global

Question 15

What is the purpose of module.exports in a Node.js module?

Answer 15

It exports a module so other modules can use it

Question 16

How do you import functionality into a Node.js module from another Node.js module?

Answer 16

Using the require function

Question 17

What is the JavaScript Event Loop?

Answer 17

looks at stack and task queue, if stack is empty, it takes first task from queue and runs it

Question 18

What is different between “blocking” and “non-blocking” with respect to how code is executed?

Answer 18

Blocking assignment executes “in series” because a blocking assignment blocks execution of the next statement until it completes. … Non-blocking assignment executes in parallel because it describes assignments that all occur at the same time.

Question 19

What is a directory?

Answer 19

A location for storing files

Question 20

What is a relative file path?

Answer 20

location relative to where file is

Question 21

What is an absolute file path?

Answer 21

Full location of file

It starts with a forward slash /

meaning root of file system

Question 22

What module does Node.js include for manipulating the file system?

Answer 22

fs module

Question 23

What method is available in the Node.js fs module for writing data to a file?

Answer 23

fs.writeFile

Question 24

Are file operations using the fs module synchronous or asynchronous?

Answer 24

Both, since there are different sync versions, but fs.writeFile is asynchronous

Asynchronous take callback arguments