Handling clicks

What this means

Event handlers are functions that run after a user action. In JSX, click handlers use onClick and receive a function.

In beginner terms, this topic answers one practical question: "What should I write, and why does React care about it?" Do not try to memorize the syntax first. First understand the idea, then connect the syntax to that idea.

Why it matters

Events connect the visible interface to behavior. Buttons, menus, forms, and toggles all depend on event handlers.

When you build real React screens, this idea helps you decide where data should live, what the user should see, and what should happen after an interaction. That is why this lesson is part of the main path instead of being an optional detail.

Step by step

1. Notice the UI problem this topic solves. 2. Look at the smallest possible example. 3. Change one value and predict what should appear. 4. Run the example and compare the result with your prediction. 5. Use the practice task before moving on.

Small example

<button onClick={() => setOpen(true)}>Open</button>

Common mistake

Do not write onClick={setOpen(true)} because that calls the setter while rendering. Pass a function instead.

Practice task

Build a button that changes a message from Waiting to Clicked.

Remember this

Pass a function to event props.