Event types

What this means

React events have types like React.ChangeEvent<HTMLInputElement> for input changes and React.FormEvent<HTMLFormElement> for form submission.

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

Event types help you access the right properties, such as event.target.value for inputs or event.preventDefault() for forms.

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

function handleSubmit(event: React.FormEvent<HTMLFormElement>) {
  event.preventDefault();
}

Common mistake

Do not guess event shapes. Use the element type to choose the right event type.

Practice task

Write a typed change handler for an input value.

Remember this

Event types connect handlers to the element they handle.