Functions

What this means

A function is a reusable block of code. You can call it when you want those steps to run.

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

Functions prevent repeated code and make behavior easier to name, test, and understand.

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 greet(name) {
  return `Hello ${name}`;
}

Common mistake

Do not make one function do too many unrelated jobs. A function should have a clear purpose.

Practice task

Create a function that receives a lesson name and returns a friendly message.

Remember this

Functions name behavior.