Tutorials

Master the JavaScript Event Loop with easy-to-understand examples. Learn about the Call Stack, Web APIs, Callback Queue, Microtask Queue, Promises, async/await, and interview questions.

Learn how to solve the JavaScript `createCounter` problem using closures. Understand why `num++` behaves the way it does and write the optimal solution.

Learn whether you can change a const value in JavaScript. Understand primitive vs reference types, objects, arrays, and why const doesn't always mean immutable.

A small calculator is a perfect way to understand two core JavaScript ideas at once — the factory function pattern and closures. Here's how a single function can create an object whose methods remember a value long after the function has run.