Clean Code Principles That Actually Matter

"Clean code" has become a buzzword in software development, but what does it actually mean in practice? Here are the principles that make a real difference.

1. Names Should Tell a Story

Good naming is about communication, not brevity:

// Unclear
const d = user.createdAt;
const isValid = d > threshold;

// Clear
const userCreationDate = user.createdAt;
const isRecentUser = userCreationDate > recentUserThreshold;

2. Functions Should Do One Thing Well

The single responsibility principle applies to functions too:

// Doing too much
function processUser(user) {
  // validate user
  // save to database
  // send email
  // log activity
}

// Better approach
function validateUser(user) { /* ... */ }
function saveUser(user) { /* ... */ }
function notifyUser(user) { /* ... */ }
function logUserActivity(user) { /* ... */ }

3. Make the Happy Path Obvious

Structure your code so the main flow is clear:

// Hidden happy path
function processPayment(payment) {
  if (payment.amount <= 0) {
    throw new Error('Invalid amount');
  }
  if (!payment.method) {
    throw new Error('Payment method required');
  }
  if (!payment.currency) {
    throw new Error('Currency required');
  }
  
  // The actual work is buried here
  return chargeCard(payment);
}

// Clear happy path
function processPayment(payment) {
  validatePayment(payment);
  return chargeCard(payment);
}

4. Comments Should Explain Why, Not What

Code should be self-documenting. Comments should provide context:

// Bad comment
// Increment i by 1
i++;

// Good comment
// Retry up to 3 times to handle transient network errors
for (let attempt = 1; attempt <= MAX_RETRIES; attempt++) {
  // ...
}

5. Embrace Early Returns

Reduce nesting and make your code more readable:

// Nested conditions
function getUser(id) {
  if (id) {
    if (typeof id === 'string') {
      if (id.length > 0) {
        return database.findUser(id);
      }
    }
  }
  return null;
}

// Early returns
function getUser(id) {
  if (!id) return null;
  if (typeof id !== 'string') return null;
  if (id.length === 0) return null;
  
  return database.findUser(id);
}

Conclusion

Clean code isn't about following rules dogmatically—it's about making your code easier to understand, modify, and maintain. Focus on clarity and communication, and the rest will follow.