Top 10 JavaScript Best Practices

JavaScript is one of the most widely used programming languages, powering everything from web applications to backend services. However, writing clean, efficient, and maintainable JavaScript code requires following best practices.

In this article, we will explore the top 10 JavaScript best practices that every developer should follow to write robust and scalable applications.

For non-members, read this article for free on my blog: Top 10 JavaScript Best Practices.

1. Use let and const Instead of var

Using var can lead to unexpected behavior due to function-scoping and hoisting issues. Instead, use let and const for better scoping and readability.

✅ Good Practice (let and const)

const name = "John";  // Cannot be reassigned
let age = 25;         // Can be reassigned
age = 30;

❌ Bad Practice (var)

var name = "John";
var age = 25;
var age = 30;  // Re-declaring can cause unintended side effects

🔹 Why?

• let and const provide block-scoping.
• Prevents accidental re-declarations.

📌 Tip: Use const for constants and let for variables that may change.

2. Always Use Strict Mode

Strict mode helps catch common JavaScript errors and prevents accidental global variable…