Node.js Flashcards
What is Node.js?
A program that allows JavaScript to be run outside of a web browser.
What can Node.js be used for?
It is commonly used to build back ends for Web applications, command-line programs, or any kind of automation that developers wish to perform.
What is a REPL?
Read-eval-print_loop; A simple development environment that takes single user inputs executes them, and returns the result to the user.
When was Node.js created?
Node.js was created in 2009 by Ryan Dahl.
What back end languages have you heard of?
PHP, Java, Ruby, and Python
What is a computer process?
An instruction currently being carried out by the computer.
Roughly how many computer processes are running on your host operating system (Task Manager or Activity Monitor)?
100+
Why should a full stack Web developer know that computer processes exist?
So you can understand how the computer interprets instructions and make your programs more efficient.
What is the process object in a Node.js program?
A global object that provides information about, and control over, the current Node.js process.
How do you access the process object in a Node.js program?
Since it’s a global object you can just reference it by name.
What is the data type of process.argv in Node.js?
An array of strings.
What is a JavaScript module?
A JavaScript file.
What values are passed into a Node.js module’s local scope?
__filename, __dirname, require, exports, module
Give two examples of truly global variables in a Node.js program.
console, process, setInterval, setTimeout, clearInterval, clearTimeout, global
What is the purpose of module.exports in a Node.js module?
So that we can access files from elsewhere in the code (another module).
How do you import functionality into a Node.js module from another Node.js module?
With the require method.
What is the JavaScript Event Loop?
The event loop checks if the stack is clear so it can push callbacks to the stack from the task queue.
What is different between “blocking” and “non-blocking” with respect to how code is executed?
‘blocking’ code is on the stack, ‘non-blocking’ is on the queue.
What is a directory?
A location for storing files.
What is a relative file path?
A path to another file based off of the current location.
What is an absolute file path?
A path to a file based off of the root directory.
What module does Node.js include for manipulating the file system?
The fs module.
What method is available in the Node.js fs module for writing data to a file?
fs.writeFile( file, data, callback)
Are file operations using the fs module synchronous or asynchronous?
Asynchronous
