LESSON 30

JavaScript Review Challenge

Learning objective: Combine variables, logic, functions, and the DOM.

Understand

This challenge ties the JavaScript fundamentals together.

You now know variables, conditions, loops, functions, arrays, objects, the DOM, events, and storage. This review asks you to build a small interactive feature that uses several of these at once.

Analogy: This is your first taste of real app logic — many small skills working as one.

See It in Action

A typical mini-feature wires an event to DOM changes:

btn.addEventListener("click", () => {
  count++;
  output.textContent = count;
});
How it works: A click updates a variable and reflects it in the DOM — combining events, variables, and content changes.

Try It Yourself

  1. Build a click counter that updates the page.
  2. Store the count so it survives a refresh.
  3. Add a reset button.

Quick Quiz

What best demonstrates your JS fundamentals here?

Challenge

Build an interactive counter that updates the DOM and remembers its value.

Success condition: Your counter updates on click and persists after a refresh.