Prerequisite

Before we start binding data and drawing circles, let’s make sure our foundation is solid.

1. Basic JavaScript (ES6)

You don’t need to be a JS wizard, but you should be comfortable with:

• Variables (const, let)
• Functions and Arrow Functions
• Arrays & Objects (and methods like .map(), .filter())
• Promises and async/await (for loading data)

2. HTML & CSS

Knowledge of the DOM (Document Object Model) and how to style elements with CSS will make your D3 journey much smoother.

3. Basic Math

A little bit of geometry and algebra helps with layouts, but don’t worry—D3 handles the heavy lifting of coordinate calculations for you!

🧠 Check Your Readiness

Before moving on, let’s do a quick check.