20 Must-Know React.js Techniques for Beginners in 2025

Welcome to the exciting world of React.js! Whether you're just starting out or looking to deepen your understanding, mastering these 20 techniques will set you on a path to becoming a proficient React developer. Let's dive in and explore the essential tips and tricks that will make your journey both enjoyable and productive.

1. Understand JSX Basics

JSX is a syntax extension for JavaScript that looks similar to XML or HTML. It's a fundamental part of React, allowing you to write HTML-like code within JavaScript. Embrace JSX as it makes your code more readable and easier to write.

Example:

const element = <h1>Hello, world!</h1>;

2. Component-Based Architecture

React is all about components. Break down your UI into reusable pieces to manage and build your application more efficiently. Think of components as building blocks that can be assembled in various ways.

Example:

function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}

3. Functional vs. Class Components

Start with functional components, as they are simpler and easier to understand. Once you're comfortable, explore class components to grasp the full spectrum of React's capabilities.

Example:

// Functional Component
function Greeting({ name }) {
  return <h1>Hello, {name}!</h1>;
}

// Class Component
class Greeting extends React.Component {
  render() {
    return <h1>Hello, {this.props.name}!</h1>;
  }
}

4. State Management

Understanding state is crucial. Use the useState hook in functional components to manage local state. Remember, state should be kept as simple as possible to avoid complexity.

Example:

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

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

5. Props Drilling

Pass data between components using props. While it's straightforward, be mindful of prop drilling—passing props through multiple layers of components—which can make your code harder to maintain.

Example:

function Parent() {
  return <Child message="Hello from Parent!" />;
}

function Child({ message }) {
  return <p>{message}</p>;
}

6. Lifting State Up

When multiple components need to share state, lift it up to their closest common ancestor. This technique helps in maintaining a single source of truth for your data.

Example:

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

  return (
    <div>
      <Child count={count} />
      <button onClick={() => setCount(count + 1)}>Increment</button>
    </div>
  );
}

function Child({ count }) {
  return <p>Count: {count}</p>;
}

7. Hooks: Your New Best Friends

Hooks like useEffect, useContext, and custom hooks are game-changers. They allow you to use state and other React features in functional components, making your code more concise and reusable.

Example:

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

  useEffect(() => {
    document.title = `You clicked ${count} times`;
  }, [count]);

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

8. Context API for Global State

For managing global state, the Context API is a lifesaver. It allows you to pass data through the component tree without having to pass props down manually at every level.

Example:

const MyContext = React.createContext();

function Parent() {
  const value = "Hello from Context!";
  return (
    <MyContext.Provider value={value}>
      <Child />
    </MyContext.Provider>
  );
}

function Child() {
  return <GrandChild />;
}

function GrandChild() {
  const value = useContext(MyContext);
  return <p>{value}</p>;
}

9. Conditional Rendering

Render components conditionally based on state or props. Use JavaScript's logical operators to control what gets displayed, making your UI dynamic and responsive.

Example:

function Greeting({ isLoggedIn }) {
  return isLoggedIn ? <h1>Welcome back!</h1> : <h1>Please sign up.</h1>;
}

10. Lists and Keys

When rendering lists, always provide a unique key prop to each element. This helps React identify which items have changed, are added, or are removed, optimizing the rendering process.

Example:

function ItemList({ items }) {
  return (
    <ul>
      {items.map((item) => (
        <li key={item.id}>{item.name}</li>
      ))}
    </ul>
  );
}

11. Event Handling

Handling events in React is straightforward. Define your event handlers as functions and pass them as props to your components. Remember to use synthetic events provided by React.

Example:

function Button() {
  const handleClick = () => {
    alert('Button clicked!');
  };

  return <button onClick={handleClick}>Click me</button>;
}

12. Controlled Components

Use controlled components for form inputs. By keeping the form data in the component's state, you have a single source of truth, making it easier to manage and validate input.

Example:

function Form() {
  const [name, setName] = useState('');

  const handleChange = (event) => {
    setName(event.target.value);
  };

  return (
    <input type="text" value={name} onChange={handleChange} />
  );
}

13. Error Boundaries

Error boundaries catch JavaScript errors anywhere in their child component tree, log those errors, and display a fallback UI instead of the component tree that crashed. They improve the user experience by preventing the entire app from crashing.

Example:

class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error) {
    return { hasError: true };
  }

  componentDidCatch(error, errorInfo) {
    console.log(error, errorInfo);
  }

  render() {
    if (this.state.hasError) {
      return <h1>Something went wrong.</h1>;
    }

    return this.props.children;
  }
}

14. Code Splitting and Lazy Loading

Improve your app's performance with code splitting and lazy loading. Use React's React.lazy and Suspense to load components only when they are needed, reducing the initial load time.

Example:

const LazyComponent = React.lazy(() => import('./LazyComponent'));

function App() {
  return (
    <React.Suspense fallback={<div>Loading...</div>}>
      <LazyComponent />
    </React.Suspense>
  );
}

15. Higher-Order Components (HOC)

HOCs are a pattern for reusing component logic. They take a component and return a new component with enhanced functionality, promoting code reuse and separation of concerns.

Example:

function withLogger(WrappedComponent) {
  return class extends React.Component {
    componentDidMount() {
      console.log('Component mounted');
    }

    render() {
      return <WrappedComponent {...this.props} />;
    }
  };
}

const EnhancedComponent = withLogger(MyComponent);

16. Custom Hooks

Create custom hooks to encapsulate and reuse stateful logic. They allow you to extract component logic into reusable functions, making your components cleaner and more focused.

Example:

function useWindowWidth() {
  const [width, setWidth] = useState(window.innerWidth);

  useEffect(() => {
    const handleResize = () => setWidth(window.innerWidth);
    window.addEventListener('resize', handleResize);
    return () => window.removeEventListener('resize', handleResize);
  }, []);

  return width;
}

17. React Router for Navigation

For single-page applications, React Router is essential. It allows you to define routes and navigate between different views, providing a seamless user experience.

Example:

import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';

function App() {
  return (
    <Router>
      <Switch>
        <Route path="/about" component={About} />
        <Route path="/home" component={Home} />
      </Switch>
    </Router>
  );
}

18. Styling Components

Explore different styling options like CSS Modules, styled-components, or even plain CSS. Choose the one that best fits your project's needs and your team's preferences.

Example:

// Using styled-components
import styled from 'styled-components';

const Button = styled.button`
  background-color: blue;
  color: white;
`;

19. Testing with Jest and React Testing Library

Write tests to ensure your components work as expected. Jest and React Testing Library are popular choices that integrate well with React, helping you catch bugs early.

Example:

import { render, screen } from '@testing-library/react';
import '@testing-library/jest-dom/extend-expect';
import App from './App';

test('renders learn react link', () => {
  render(<App />);
  const linkElement = screen.getByText(/learn react/i);
  expect(linkElement).toBeInTheDocument();
});

20. Performance Optimization

Optimize your app's performance by using techniques like memoization with React.memo and useMemo, and avoiding unnecessary re-renders. Profile your app using React's built-in tools to identify bottlenecks.

Example:

const MyComponent = React.memo(({ data }) => {
  return <div>{data}</div>;
});

function Parent({ data }) {
  const memoizedData = useMemo(() => expensiveComputation(data), [data]);
  return <MyComponent data={memoizedData} />;
}

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Conclusion

Congratulations on taking the first steps into the world of React.js! By mastering these 20 techniques, you'll be well on your way to building robust and efficient web applications. Embrace the learning journey, experiment with new ideas, and most importantly, have fun coding!

If you found this guide helpful, I'd love for you to follow me on GitHub at sovannaro for more coding tips, projects, and updates. Let's connect and grow together in the React community!

Happy coding! 🎉💻