Separation of Concerns in JavaScript: Quiz and Flashcards

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Questions and Answers

What is the purpose of using modules in Node.js?

To enhance code organization and reusability (correct)

To reduce the file size of the application

To make the code run faster

To confuse developers with additional syntax

How can you access built-in modules in Node.js?

By importing them using import keyword

By declaring them in a separate file

By directly calling them in the code

Using the require() function (correct)

What is the purpose of the module wrapper function in Node.js?

Automatically exporting all variables within the module

Encapsulating the module code within a function (correct)

Preventing other modules from accessing the current module

Forcibly caching the module's content

How does Node.js achieve module caching?

By storing a copy of the module's exports object after the first require() call Signup and view all the answers

In Node.js, how can you create and use local modules?

By defining reusable code blocks specific to your project and storing them within the project directory Signup and view all the answers

What does module.exports do in Node.js?

Exports an object that represents the module's public interface Signup and view all the answers

What is the purpose of the module wrapper function in Node.js?

To load and execute the module code and cache the module's exports object Signup and view all the answers

Why does Node.js use module caching?

To improve performance by caching the result of loading and compiling modules Signup and view all the answers

What happens when a module is cached in Node.js?

It is stored and its exports object is cached for subsequent use Signup and view all the answers

Which tool is used for managing project dependencies in Node.js?

NPM (Node Package Manager) Signup and view all the answers

What is the purpose of creating a package.json file in Node.js?

To provide general information about the project and manage dependencies Signup and view all the answers

Where are modules stored in a Node.js application?

Inside the app's node_modules folder Signup and view all the answers

What does Node.js do before executing a module's code?

Wraps it with a function wrapper Signup and view all the answers

Why does Node.js utilize module caching?

To improve performance by caching loaded and compiled modules Signup and view all the answers

How does Node.js handle the caching of modules?

Load, execute the module code, and cache the module's exports object Signup and view all the answers

In Node.js, what is the purpose of the module wrapper function?

Wraps any code inside a JavaScript file before execution Signup and view all the answers

How can you share functions and variables between modules in Node.js?

Using module.exports to export functions and variables Signup and view all the answers

What is one way to create and use local modules in Node.js?

Using relative paths to require them in your application Signup and view all the answers

Which file is created when initializing npm and going through all settings?

package.json Signup and view all the answers

What is the purpose of devDependencies in a Node.js project?

Only necessary for development Signup and view all the answers

When setting up a Node.js project, what will applications include?

dependencies and devDependencies Signup and view all the answers

What does the '-y' flag do when adding dependencies using npm?

Select all defaults automatically Signup and view all the answers

Why is separating dependencies and devDependencies in a Node.js project considered a helpful practice?

To determine which dependencies are only for development Signup and view all the answers

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

To bundle all code within a function scope Signup and view all the answers

How does Node.js achieve module caching?

By storing modules in a centralized module cache for reuse Signup and view all the answers

What is the purpose of the `require()` function in Node.js?

To import built-in modules or dependencies Signup and view all the answers

When setting up a Node.js project, what is the role of a package.json file?

Define the project's dependencies and metadata Signup and view all the answers

What role does NPM play in managing dependencies in Node.js projects?

Handles installation, updating, and removal of project dependencies Signup and view all the answers

In Node.js, what is the main benefit of module caching?

Improves application performance by reducing duplicate loading Signup and view all the answers

What is the purpose of the module wrapper function in Node.js?

To wrap the entire code inside a function before execution Signup and view all the answers

How does module caching work in Node.js?

It saves modules globally to prevent them from being loaded multiple times Signup and view all the answers

What does the `module.exports` syntax achieve in Node.js?

It allows selective exporting of variables and functions Signup and view all the answers

In Node.js, how can you create and use local modules?

By using <code>module.exports</code> and <code>require</code> syntax Signup and view all the answers

What happens if you don't use `module.exports` in a Node.js module?

The functions and variables within the module are private to that module only Signup and view all the answers

Why is it essential to promote separation of concerns within an application?

To improve reusability and maintainability of the codebase Signup and view all the answers

Study Notes

Node.js Modules

Modules are reusable blocks of code that provide functionalities you can integrate into your applications, promoting code organization, reusability, and separation of concerns.

Built-in Modules

Built-in modules come bundled with Node.js installation, providing essential functionalities for common tasks like file system access, networking, I/O operations, etc.
Can be accessed using the require() function in your code.
Examples: const OS = require('os'); console.log(OS.arch())

Local (User-defined) Modules

Local modules are reusable code blocks created specifically for your project and stored within the project directory.
Offer a way to organize your codebase, improve reusability, and promote separation of concerns within your application.
Local module is just a file with a .js extension (e.g., test.js).

Module Wrapper

NodeJS wraps the entire code inside a function before execution, known as the Module Wrapper Function.
The Module Wrapper Function has the following structure: __dirname, __filename are variables that hold the name and directory of the current module.

Module Caching

Module caching is a feature that helps improve performance by caching the result of loading and compiling modules.
When a module is required by another module, Node.js will load and execute the module code, and then cache the module's exports object.

NPM (Node Package Manager)

NPM is a tool for managing project dependencies via the command line and a website hosting over 1 million third-party packages.
Modules are shared as packages, which extend the functionality of your app, and are stored in the app's node_modules folder.

Initializing NPM and Creating a package.json file

Initializing npm will create a package.json file within the root of your application folder, containing general information about the project.
Can be initialized using the command-line: npm init, or with defaults: npm init -y.

Adding Dependencies

Applications can include both dependencies and devDependencies, or just dependencies.
devDependencies are thought of as dependencies that are only necessary for development.
Adding dependencies can be done using the npm install command.

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Test your knowledge on organizing codebase, improving reusability, and promoting separation of concerns in JavaScript applications. Learn about local modules in JavaScript and how module.exports can be used to define functions and variables across modules.

JavaScript Modules and Separation of Concerns Quiz

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Questions and Answers

What is the purpose of using modules in Node.js?

How can you access built-in modules in Node.js?

What is the purpose of the module wrapper function in Node.js?

How does Node.js achieve module caching?

In Node.js, how can you create and use local modules?

What does module.exports do in Node.js?

What is the purpose of the module wrapper function in Node.js?

Why does Node.js use module caching?

What happens when a module is cached in Node.js?

Which tool is used for managing project dependencies in Node.js?

What is the purpose of creating a package.json file in Node.js?

Where are modules stored in a Node.js application?

What does Node.js do before executing a module's code?

Why does Node.js utilize module caching?

How does Node.js handle the caching of modules?

In Node.js, what is the purpose of the module wrapper function?

How can you share functions and variables between modules in Node.js?

What is one way to create and use local modules in Node.js?

Which file is created when initializing npm and going through all settings?

What is the purpose of devDependencies in a Node.js project?

When setting up a Node.js project, what will applications include?

What does the '-y' flag do when adding dependencies using npm?

Why is separating dependencies and devDependencies in a Node.js project considered a helpful practice?

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

How does Node.js achieve module caching?

What is the purpose of the require() function in Node.js?

When setting up a Node.js project, what is the role of a package.json file?

What role does NPM play in managing dependencies in Node.js projects?

In Node.js, what is the main benefit of module caching?

What is the purpose of the module wrapper function in Node.js?

How does module caching work in Node.js?

What does the module.exports syntax achieve in Node.js?

In Node.js, how can you create and use local modules?

What happens if you don't use module.exports in a Node.js module?

Why is it essential to promote separation of concerns within an application?

Study Notes

Node.js Modules

Built-in Modules

Local (User-defined) Modules

Module Wrapper

Module Caching

NPM (Node Package Manager)

Initializing NPM and Creating a package.json file

Adding Dependencies

Studying That Suits You

Description

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