Node.js
/Beginner
Global Objects
Definition
Variables and functions that are globally available in all Node.js modules without needing to be imported via `require()`.
Explain Like I'm New
These are built-in cheat codes. Instead of importing `console` or `setTimeout` into every single file, Node injects them globally so you can use them immediately anywhere in your app.
Real World Example
Using `__dirname` to dynamically find the current folder path so you can read a configuration file safely, regardless of where the app was launched from.
Common Use Cases
- •Path resolution
- •Timers
- •Environment variable access
Terminal Output
bash / terminal
// GLOBAL VARIABLES (No imports needed!)
// 1. console (Prints to stdout/stderr)
console.log("I am globally available!");
// 2. Timers
// setTimeout(() => console.log("Timer finished"), 1000);
// 3. Current Directory and File (In CommonJS)
// Note: These don't work in standard ES Modules unless specifically enabled
console.log("Current Directory:", __dirname);
console.log("Current File:", __filename);
// 4. The 'process' object (Information about the running app)
console.log("Node Version:", process.version);
console.log("Platform:", process.platform);
// 5. The actual root global object (equivalent to 'window' in browsers)
// You can attach things to it (but it's considered bad practice)
global.myCustomAppSecret = "12345";
console.log(global.myCustomAppSecret);
Interview Questions
basic
- Name three global objects in Node.js.
intermediate
- What is the difference between `__dirname` and `__filename`?
advanced
- Are `module`, `require`, and `exports` truly global objects?