Top 10 Best Practices for Writing Clean Code

Writing clean code is a critical skill for every software developer. Clean code is easier to read, maintain, and scale. It reduces bugs and makes onboarding new developers a smoother process. In this blog, we’ll go over the top 10 best practices for writing clean, efficient, and maintainable code.

1. Meaningful Variable and Function Names

Naming is one of the most important aspects of clean code. Use names that describe the purpose of variables, functions, and classes. Avoid generic names like temp, x, or foo. Instead, use meaningful names like userEmail, calculateTotalPrice, or isValidPassword.

Example:

// Poor Naming
let t = 10;
function x() {
    // code
}

// Clean Naming
let maxLoginAttempts = 10;
function validateUserInput() {
    // code
}

Why It’s Important: Meaningful names improve readability, making the code self-explanatory, even for those unfamiliar with it.

---

2. Keep Functions Small and Focused

A good function should perform one task and do it well. Large, monolithic functions can be hard to understand and maintain. Break down complex logic into smaller, manageable functions.

Example:

// Large function doing multiple things
function processOrder(order) {
    validateOrder(order);
    applyDiscount(order);
    updateInventory(order);
    notifyCustomer(order);
}

// Clean: Split into smaller functions
function processOrder(order) {
    validateOrder(order);
    applyDiscount(order);
    updateInventory(order);
    notifyCustomer(order);
}

Why It’s Important: Smaller functions are easier to test, debug, and maintain.

---

3. Comment Only When Necessary

Well-written code should be self-explanatory. Comments are useful for explaining why something is done, but not what is done. Over-commenting can clutter the code. Focus on making your code readable enough that it doesn’t need comments to explain what it does.

Example:

// Bad: Commenting obvious code
let age = 25; // Store age of the person

// Good: Explain complex logic
// We use binary search to improve search performance
function searchElement(arr, target) {
    // code
}

Why It’s Important: Over-commenting adds noise, but clear code with essential comments is much easier to follow.

---

4. Use Consistent Formatting

Adopt a consistent style for indentation, spacing, and bracing across your project. Many teams use style guides like Prettier or ESLint in JavaScript, or Black in Python to enforce uniformity in formatting.

Example:

// Inconsistent Formatting
function doSomething(){let x=5;return x;}

// Consistent Formatting
function doSomething() {
    let x = 5;
    return x;
}

Why It’s Important: Consistent formatting ensures that your code looks clean and readable to anyone reviewing it.

---

5. Avoid Deep Nesting

Deeply nested loops or conditions make code hard to read and understand. Refactor them by returning early from functions, or using guard clauses to handle special cases.

Example:

// Bad: Deep nesting
if (user) {
    if (user.isActive) {
        if (user.hasPermission) {
            // Do something
        }
    }
}

// Good: Early return
if (!user || !user.isActive || !user.hasPermission) {
    return;
}
// Do something

Why It’s Important: Reducing nesting simplifies the control flow, making the code easier to follow.

---

6. DRY (Don’t Repeat Yourself)

Repeating code in multiple places can lead to inconsistencies and make your codebase harder to maintain. Abstract out repetitive logic into reusable functions or modules.

Example:

// Repeated code
validateEmail(user.email);
validateEmail(admin.email);

// Clean: Reuse function
function validateEmail(email) {
    // validation logic
}

validateEmail(user.email);
validateEmail(admin.email);

Why It’s Important: DRY principles ensure that changes are made in one place, reducing bugs and improving maintainability.

---

7. Write Unit Tests

Clean code goes hand-in-hand with testable code. Unit tests verify that each part of your code works as expected. Aim for high test coverage so that future changes don’t introduce bugs.

Example:

function add(a, b) {
    return a + b;
}

// Unit test
test('add function should return correct sum', () => {
    expect(add(2, 3)).toBe(5);
});

Why It’s Important: Unit tests help catch bugs early and ensure that new changes don’t break existing functionality.

---

8. Handle Errors Gracefully

Don’t ignore errors or handle them in a way that hides their causes. Provide meaningful error messages, and handle exceptions where they’re most appropriate.

Example:

// Bad: Generic error handling
try {
    processData();
} catch (e) {
    console.log('Error occurred');
}

// Good: Descriptive error handling
try {
    processData();
} catch (e) {
    console.log(`Error processing data: ${e.message}`);
}

Why It’s Important: Detailed error handling ensures that issues can be quickly identified and fixed.

---

9. Refactor Regularly

Refactoring is the process of restructuring existing code without changing its external behavior. Regular refactoring keeps your code clean, prevents technical debt, and improves maintainability.

Example:

// Before refactoring: large, cluttered function
function calculatePrice(items, tax) {
    let total = 0;
    for (let item of items) {
        total += item.price;
    }
    return total * tax;
}

// After refactoring: clearer logic
function calculateTotal(items) {
    return items.reduce((sum, item) => sum + item.price, 0);
}

function calculatePrice(items, tax) {
    return calculateTotal(items) * tax;
}

Why It’s Important: Continuous refactoring keeps your codebase clean and prevents issues from snowballing.

---

10. Keep Dependencies to a Minimum

Using external libraries can save time, but it also introduces complexity and increases the risk of security vulnerabilities. Always evaluate whether a library is necessary or if it’s something you can build yourself with minimal effort.

Example:

// Bad: Using a library for a simple task
import {capitalize} from 'some-library';
capitalize('hello');

// Good: Simple task done natively
const capitalize = (str) => str.charAt(0).toUpperCase() + str.slice(1);

Why It’s Important: Reducing dependencies makes your code easier to manage and reduces the risk of issues stemming from third-party libraries.

---

Writing clean code isn’t just about aesthetics—it’s about creating code that is readable, maintainable, and less prone to bugs. By adopting these 10 best practices, you’ll not only improve the quality of your code but also make your life, and the lives of your fellow developers, much easier.

Key Takeaways:

• Use meaningful names and keep your functions small.
• Write code that is self-explanatory, and only comment when necessary.
• Apply consistent formatting and avoid deep nesting.
• Keep your code DRY, handle errors properly, and refactor regularly.
• Write unit tests and minimize external dependencies.

Happy coding!