Writing Clean JavaScript

Writing clean JavaScript means creating code that is easy to read, maintain, and debug. Clean code reduces errors and improves collaboration.

1. Use Meaningful Variable and Function Names

Choose descriptive names that clearly explain the purpose of variables and functions.

2. Keep Functions Small and Focused

Each function should perform a single task. This makes debugging and testing easier.

3. Use Consistent Formatting and Indentation

Indent code blocks properly and follow a consistent style for braces, spaces, and line breaks.

4. Avoid Global Variables

Global variables can lead to conflicts and bugs. Use local variables or encapsulate code inside functions or modules.

5. Use Comments Sparingly and Effectively

Comments should explain why something is done, not what the code does. Well-written code often needs fewer comments.

6. Prefer Const and Let Over Var

Use const for variables that don’t change and let for those that do. Avoid var to prevent scope-related bugs.

const maxUsers = 100;
let currentUsers = 0;

function addUser() {
  if (currentUsers < maxUsers) {
    currentUsers++;
  }
}

7. Use Early Returns to Reduce Nesting

Return early from functions when possible to avoid deep nesting and improve readability.

function isAdult(age) {
  if (age < 18) return false;
  return true;
}

8. Avoid Magic Numbers and Strings

Replace unexplained literals with named constants.

const MAX_ATTEMPTS = 5;

for (let i = 0; i < MAX_ATTEMPTS; i++) {
  // attempt login
}