node

Question 1

What is Node.js?

Answer 1

JavaScript outside of a browser.

Question 2

What can Node.js be used for?

Answer 2

build backend

Question 3

What is a REPL?

Answer 3

read eval print loop. Browser console is a REPL. interactive shell that processes node.js expressions.

Question 4

When was Node.js created?

Answer 4

May 27th, 2009 by Ryan Dahl

Question 5

What back end languages have you heard of?

Answer 5

Python, PHP, Perl, JavaScript, Lua

Question 6

What is a computer process?

Answer 6

the instance of a computer program that is being executed by one or many threads.

Question 7

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

Answer 7

500

Question 8

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

Answer 8

Full stack Web development is based on making multiple processes work together to form one application. Important to know that application has many parts.

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. JavaScript object that is a model of Node Js computer process.

Question 10

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

Answer 10

Just process because it is global

Question 11

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

Answer 11

an array of strings

Question 12

What is a JavaScript module?

Answer 12

a single ‘.js’ file. Modules are way to split an application into separate files instead of having all your application in one file. Allows you to establish values that you want to use on other modules.

Question 13

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

Answer 13

__filename, __dirname, exports, module, require

Question 14

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

Answer 14

console, process, url.

Question 15

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

Answer 15

so that you can reuse that function in other modules. you are exporting that to somewhere else.

Question 16

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

Answer 16

using require function and relative url to .

Question 17

What is the JavaScript Event Loop?

Answer 17

If the stack is empty, it takes the first task on the queue and pushes it on to the stack. System of managing JavaScript workloads. Looks to see if call stack is busy, if there is something in call stack does nothing. looks at queue stack and if there is a task, pushes that to call stack.

Question 18

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

Answer 18

Blocking refers to operations that block further execution until that operation finishes while non-blocking refers to code that doesn’t block execution. blocking means whatever is occupying the call stack (async). non-blocking means sync.

Question 19

What is a directory?

Answer 19

file system used to control how data is stored and retrieved. File that lists other files.

Question 20

What is a relative file path?

Answer 20

file path relative to the current file.

Question 21

What is an absolute file path?

Answer 21

full url to a file. file path starting from the root file to specific file.

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

js.writeFile

Question 24

Are file operations using the fs module synchronous or asynchronous?

Answer 24

asynchronous