Node.js Essentials Quiz: Fundamentals for Beginners Quiz

Explore core Node.js basics with this comprehensive quiz designed for beginners, covering modules, event handling, asynchronous code, and practical usage. Reinforce your knowledge of Node.js concepts, syntax, and best practices to improve your skills and understanding of server-side JavaScript.

1. Node.js Runtime Environment

   Which statement best describes Node.js as a runtime?

   1. Node.js executes JavaScript code outside a web browser.
   2. Node.js is used exclusively for building desktop applications.
   3. Node.js runs only in web browsers as a plugin.
   4. Node.js requires compiling Java code to work properly.

   Explanation: Node.js enables JavaScript to run outside of web browsers, allowing server-side applications. The option about running only in browsers is incorrect, as Node.js works on servers and desktops. Node.js does not require Java code compilation, making the Java-related statement incorrect. While Node.js can be used for desktop applications, it is not exclusive to them.

2. Modules in Node.js

   How do you include a built-in module like 'fs' for file operations in Node.js?

   1. use('fs');
   2. const fs = require('fs');
   3. var fs = importModule('fs');
   4. import module.fs;

   Explanation: The correct way to include modules in Node.js uses the require function, such as const fs = require('fs');. The statement 'import module.fs;' is invalid syntax. 'var fs = importModule('fs');' is not a standard Node.js method. 'use('fs');' does not exist in Node.js for loading modules.

3. Asynchronous Code Handling

   Which feature in Node.js is designed for handling asynchronous operations like reading files?

   1. Infinite loops
   2. Static typing
   3. Synchronous blocks
   4. Callback functions

   Explanation: Callback functions allow Node.js to process tasks asynchronously by running code after an operation finishes. Synchronous blocks execute code sequentially and can block the thread, making them unsuitable for non-blocking operations. Infinite loops do not relate to handling async events and can freeze the application. Static typing is not involved in managing asynchronous logic.

4. Global Objects

   Which global object provides the path of the current file in Node.js?

   1. __mainfile
   2. thisFile
   3. __filename
   4. filePath

   Explanation: The __filename global variable gives the full path and name of the currently-executing file in Node.js. The options 'filePath', 'thisFile', and '__mainfile' are not valid predefined Node.js global objects, making them incorrect choices.

5. Creating a Simple HTTP Server

   Which core module is required to create an HTTP server in Node.js?

   1. http
   2. webserver
   3. networks
   4. request

   Explanation: The 'http' module is the built-in Node.js module for creating HTTP servers and handling requests. 'Networks' and 'webserver' are not standard modules in Node.js. 'request' used to be a common external package, but it is not a built-in module.

6. Reading Environment Variables

   How do you access an environment variable named 'PORT' inside a Node.js script?

   1. process.env.PORT
   2. this.env.PORT
   3. PORT.getEnv()
   4. env.PORT

   Explanation: Environment variables in Node.js are accessed through the 'process.env' object, so process.env.PORT is correct. There are no built-in 'env' or 'this.env' objects in Node.js, and 'PORT.getEnv()' is not a valid function.

7. Node.js Package Management

   Which tool is commonly used to manage packages and dependencies in Node.js projects?

   1. npm
   2. rpm
   3. gem
   4. pip

   Explanation: npm (Node Package Manager) is the standard tool for managing packages in Node.js projects. 'rpm' is related to Linux package management. 'pip' is used for Python, and 'gem' is associated with Ruby, not Node.js.

8. Printing Output to Console

   What is the standard way to print a message to the console in Node.js?

   1. echo('Hello World!');
   2. System.out.println('Hello World!');
   3. print('Hello World!');
   4. console.log('Hello World!');

   Explanation: console.log() is the standard JavaScript and Node.js function for printing to the console. 'print()' is not defined in core Node.js, and 'echo()' is generally used in shell scripting or PHP. 'System.out.println()' comes from other programming languages like Java, not JavaScript.

9. Event-Driven Architecture

   What mechanism does Node.js use to respond to events such as 'data received' or 'connection closed'?

   1. Thread priorities
   2. Direct interrupts
   3. Policy handlers
   4. Event emitters and listeners

   Explanation: Event emitters and listeners are the primary pattern in Node.js for handling asynchronous events, such as network connections or data transmission. 'Policy handlers' and 'thread priorities' are not Node.js concepts, and 'direct interrupts' pertain more to low-level operating system operations.

10. Default File for Starting a Node.js App

    What is the typical default entry file name for a Node.js application?

    1. runfile.js
    2. index.js
    3. appstart.js
    4. mainfile.js

    Explanation: index.js is conventionally used as the main entry point when starting a Node.js application if no alternative is specified. The other filenames, like 'appstart.js', 'mainfile.js', and 'runfile.js', are not standard defaults although they could be used if configured.