Typing props

What this means

TypeScript lets you define the shape of props. For example, a CourseCard can require a title string and a minutes number.

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

Types catch mistakes earlier. If you pass the wrong kind of value, TypeScript can warn before the app runs.

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

type CourseCardProps = {
  title: string;
  minutes: number;
};

Common mistake

Do not use any just to silence TypeScript. It removes the safety you are trying to gain.

Practice task

Create a props type for a UserBadge with name and role strings.

Remember this

Typed props document component inputs.