React JS Explained In 10 Minutes

Introduction

This tutorial provides a concise overview of core React concepts that every developer should understand. In just 10 minutes, you will gain insights into essential features of React, enabling you to start building interactive user interfaces effectively.

Step 1: Understanding Components

• Components are the building blocks of React applications.
• They can be either class-based or functional.
• Common practices:
  • Use functional components for simpler components.
  • Use class components for more complex state management.

Practical Tip

• Keep components small and focused on a single task to enhance reusability.

Step 2: Managing State

• State is a way to manage data within a component.
• You can initialize state in class components using this.state and in functional components using the useState hook.

Example of useState Hook

import React, { useState } from 'react';

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

    return (
        <div>
            <p>You clicked {count} times</p>
            <button onClick={() => setCount(count + 1)}>
                Click me
            </button>
        </div>
    );
}

Common Pitfall

• Avoid mutating state directly. Always use the state updater function for changes.

Step 3: Props for Component Communication

• Props allow you to pass data from one component to another.
• They are read-only and help maintain a unidirectional data flow.

Example of Passing Props

function ChildComponent(props) {
    return <h1>{props.message}</h1>;
}

function ParentComponent() {
    return <ChildComponent message="Hello, World!" />;
}

Practical Tip

• Use descriptive prop names to enhance readability and maintainability.

Step 4: Lifecycle Methods (Class Components)

• Lifecycle methods are hooks that allow you to run code at specific points in a component's life.
• Key methods include:
  • componentDidMount(): Invoked immediately after a component is mounted.
  • componentDidUpdate(): Invoked immediately after updating occurs.
  • componentWillUnmount(): Cleanup before the component is removed.

Common Pitfall

• Don’t forget to clean up subscriptions or timers in componentWillUnmount() to prevent memory leaks.

Step 5: Hooks for Functional Components

• Hooks are functions that let you use state and other React features in functional components.
• Important hooks include:
  • useEffect: For performing side effects in components.
  • useContext: For accessing context values.

Example of useEffect

import React, { useEffect } from 'react';

function ExampleComponent() {
    useEffect(() => {
        console.log('Component mounted or updated');
        return () => {
            console.log('Cleanup on unmount');
        };
    }, []); // Empty array ensures it runs once on mount

    return <div>Check the console log</div>;
}

Conclusion

In this tutorial, we covered fundamental concepts in React, including components, state management, props, lifecycle methods, and hooks. These elements are crucial for building functional and efficient React applications. To deepen your knowledge, consider exploring advanced topics and building real-world projects.