Node.js Course
Node.js
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Beginner

Beginner Questions

Definition

Common theoretical questions asked in introductory Node.js interviews to verify fundamental understanding.

Explain Like I'm New

Interviewers use these questions to check if you actually know what Node.js is, or if you just memorized how to build an Express app without understanding the underlying mechanics.

Real World Example

Testing knowledge of the V8 engine, non-blocking I/O, and single-threaded execution.

Common Use Cases

  • •Entry-level backend developer interviews
  • •Full-stack developer assessments

Terminal Output

bash / terminal
// Q: What is the difference between Node.js and JavaScript in the browser? console.log("BROWSER JS:"); console.log("- Has access to the DOM (document.getElementById)."); console.log("- Has the window object."); console.log("- Cannot read/write files to the user's hard drive for security."); console.log("\nNODE.JS:"); console.log("- Has ZERO access to the DOM (document is undefined)."); console.log("- Has the global object (instead of window)."); console.log("- Can read/write files, create network servers, and access the OS kernel.");

Interview Questions

basic

  • What exactly is Node.js?

intermediate

  • Explain 'Non-blocking I/O' as if I were 5 years old.

Flash Cards

Question

What is Node.js?

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Answer

It is NOT a framework or a language. It is an open-source, cross-platform JavaScript Runtime Environment built on Chrome's V8 engine that executes JavaScript code outside of a web browser.

Question

Explain Non-blocking I/O.

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Answer

It means the waiter doesn't wait in the kitchen. When Node asks the database for data, it doesn't freeze the program waiting for the reply. It moves on to the next line of code instantly, and processes the database reply later using a callback when it's ready.