Types of Errors in Node.js

1. Definition

Errors in Node.js occur when something goes wrong during program execution. Understanding different types of errors helps in debugging and building reliable applications.

2. Syntax Errors

Occurs due to incorrect code syntax
Detected at compile time
Prevents code from running

// ❌ Missing bracket
console.log("Hello"

3. Runtime Errors

Occurs during execution
Example: accessing undefined variables
Can crash the application

let data;
console.log(data.name); // ❌ Runtime error

4. Logical Errors

No error message shown
Program runs but gives wrong output
Hard to detect

// ❌ Wrong logic
function add(a, b) {
  return a - b;
}

5. System Errors

Errors from OS or system
Example: file not found, permission denied
Common in file system or network operations

const fs = require("fs");

fs.readFile("unknown.txt", (err, data) => {
  if (err) console.error(err); // ❌ System error
});

6. Why Understanding Errors is Important

Helps in debugging code
Improves application reliability
Prevents crashes
Enhances user experience