useState basics

What this means

useState lets a component remember a value between renders. It returns the current value and a setter function that asks React to render again with the new value.

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

Without state, a component can show data but cannot remember interactions like counts, typed input, opened menus, or selected tabs.

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

const [count, setCount] = useState(0);

Common mistake

Do not change state variables directly. Use the setter function, such as setCount(1).

Practice task

Create a counter that starts at 0 and shows the current count.

Remember this

State is component memory.