Why use State?

function App() {
        let [counter, setCounter] = React.useState(0);
        const onClick = () => {
            setCounter(counter + 1);
        };

        return (
            <div>
                <h3>Total clicks: {counter}</h3>
                <button onClick={onClick}>Click me</button>
            </div>
        );
    }

React.useState(0, null) == React.useState(constant, modifier)

• modifier is automatically connected with the constant of the state and re-rendering is automatically executed once it's called.

What is the Difference Between VanillaJS and ReactJS?

• When developing web applications, developers can choose between various JavaScript (JS) libraries and frameworks or stick with plain JavaScript, often referred to as VanillaJS. Understanding the differences between VanillaJS and frameworks like ReactJS is crucial for making informed decisions about which to use in your projects.

Direct DOM Manipulation vs. Declarative UI

• VanillaJS: In VanillaJS, rendering and updating the HTML elements typically involve directly manipulating the Document Object Model (DOM). Developers need to manually grab elements from the HTML, listen for events, and update the DOM when the application's state changes. This process can become complex and hard to manage as the application grows.

document.getElementById('example').textContent = 'Hello, VanillaJS!';

• ReactJS: ReactJS, on the other hand, offers a more declarative approach to building user interfaces. Instead of manually manipulating the DOM, developers define the UI as a function of the application's state. React takes care of updating the DOM to match the UI described by the components when the state changes. This approach simplifies the development process, making it easier to manage and scale applications.

function ExampleComponent() {
  return <div>Hello, ReactJS!</div>;
}

Interactive and Reusable Components

• ReactJS introduces the concept of components, which are reusable, encapsulated elements that manage their own state. This modular approach allows for building complex UIs out of simple building blocks, improving code reusability, and testing.

Performance Optimization

• ReactJS employs a virtual DOM to minimize direct DOM manipulation, which can be a performance bottleneck in large applications. By only updating parts of the DOM that have actually changed, React can significantly improve performance compared to direct DOM manipulation in VanillaJS.
  Ecosystem and Tooling

• ReactJS benefits from a rich ecosystem, including a wide range of libraries, tools, and extensions that can accelerate development, such as state management (Redux, MobX), routing (React Router), and more.

Conclusion

• While VanillaJS gives developers complete control and is beneficial for understanding the fundamentals of web development, ReactJS offers a more structured approach that simplifies the development of complex applications, enhances code maintainability, and improves performance. Learning ReactJS can significantly benefit developers working on modern web applications, providing them with the tools and concepts needed to build efficient, scalable, and interactive user interfaces.