Node.js Flashcards
What is Node.js?
Javascript not in a browser
What can Node.js be used for?
To build backends
What is a REPL?
A shortcut for read, eval, print, loop
Ie:
Google dev tools
When was Node.js created?
In 2009 by Ryan Dahl
What back end languages have you heard of?
Python, C++, Java, C, Ruby, Perl
What is a computer process?
An instance of a program that is being executed
Roughly how many computer processes are running on your host operating system (Task Manager or Activity Monitor)?
100s or more
Why should a full stack Web developer know that computer processes exist?
So they know how much memory their app takes and the relationship between front end and backend
What is the process object in a Node.js program?
A JavaScript object in Node that is a model of the computers Node.js that is currently running
(Similar to browser Window object)
How do you access the process object in a Node.js program?
Just “process” because it’s global
What is the data type of process.argv in Node.js?
An array of strings
What is a JavaScript module?
A way to separate applications into different files
What values are passed into a Node.js module’s local scope?
Dirname, filename, require, module, exports
Give two examples of truly global variables in a Node.js program
Process + URL
What is the purpose of module.exports in a Node.js module?
It allows variables from other modules to be used
How do you import functionality into a Node.js module from another Node.js module?
Using the require function with a relative path as the argument
What is the JavaScript Event Loop?
The system of managing the order of JavaScript processes (event queue, callback queue, call stack)
What is different between “blocking” and “non-blocking” with respect to how code is executed?
Non-blocking = code can run synchronously
Blocking = whatever is currently running on the call stack
**use DMV analogy for A-synchronization
What is a directory?
A place where paths for files are kept
What is a relative file path?
A way to get from where you currently are, to another place
What is an absolute file path?
Starting from anywhere, always starts with root
What module does Node.js include for manipulating the file system?
FS
What method is available in the Node.js fs module for writing data to a file?
writeFile()
Are file operations using the fs module synchronous or asynchronous?
Both
