Comments

// This is a single-line comment
const API_URL = "http://localhost:8000"; // Inline comment after code

// Calculate total with tax
const subtotal = 99.99;
const tax = subtotal * 0.08;
const total = subtotal + tax;

/*
  This function fetches users from the API.
  It handles errors and returns an empty array
  if the request fails.
*/
async function getUsers() {
  // ...
}

// Temporarily disable a block of code:
/*
const debugData = fetchDebugInfo();
console.log(debugData);
processDebugData(debugData);
*/

/**
 * Calculate the total price with tax.
 * @param {number} subtotal - The price before tax
 * @param {number} taxRate - The tax rate as a decimal (e.g., 0.08 for 8%)
 * @returns {number} The total price including tax
 */
function calculateTotal(subtotal, taxRate) {
  return subtotal + (subtotal * taxRate);
}

// ❌ Bad: States the obvious
const age = 25; // Set age to 25

// ❌ Bad: Describes what the code does
// Loop through users and print names
for (const user of users) {
  console.log(user.name);
}

// ✅ Good: Explains WHY
// API returns dates as strings, need to convert for comparison
const createdAt = new Date(user.createdAt);

// ✅ Good: Warns about non-obvious behavior
// response.ok is false for 404/500 but fetch doesn't throw
if (!response.ok) {
  throw new Error(`HTTP error: ${response.status}`);
}