Overview of React

Hello, students! Today, we’ll begin our journey of learning React.

What is React?

React is a declarative, efficient, and flexible JavaScript library for creating user interfaces.

Declarative means you describe what you want to happen without worrying about how it will be done.

Efficient means React is very fast and lightweight.

Flexible means React can be used to create a wide variety of user interfaces.

Why use React?

There are many reasons why you might want to use React.

Here are some of them:

• React is very popular, meaning there’s a large community of developers and resources available.
• React is easy to learn, even for developers with no JavaScript experience.
• React is highly efficient, which can help improve your application’s performance.
• React is very flexible, enabling you to create complex and interactive user interfaces.

How does React work?

React works using a concept called componentization.

A component is a reusable building block used to create a part of the user interface.

Each component is responsible for rendering its own part of the DOM.

When a component’s property changes, React only renders the affected component, improving your app’s performance.

Example of a React component:

const MyComponent = () => {
  return (
    <div>
      <h1>My Component</h1>
    </div>
  );
};

This component renders a header with the text “My Component.”

React also uses a concept called state to maintain the user interface’s state.

State is a set of data that can be changed over time.

For example, a component can use state to keep track of the number of items in a shopping cart.

Example of a React component with state:

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

  return (
    <div>
      <h1>Number of items: {count}</h1>
      <button onClick={() => setCount(count + 1)}>Add item</button>
    </div>
  );
};

This component renders a header with the number of items in the shopping cart.

The “Add item” button increases the number of items in the shopping cart.

Conclusion

This was just a brief overview of React.

In the next topics, we’ll learn more about the library, including its importance, use in web development, and key concepts and terminology.