#10 Difference between class based and Functional based components in React.js

Difference between Class-based and Functional-based components in React.js: 

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✅ 1. Syntax

• Class Component:

  • Uses ES6 class syntax and extends React.Component.

  class MyComponent extends React.Component {
    render() {
      return <h1>Hello</h1>;
    }
  }
  

• Functional Component:

  • A plain JavaScript function that returns JSX.

  function MyComponent() {
    return <h1>Hello</h1>;
  }
  

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✅ 2. State Management

• Class Component:
  • Uses this.state and this.setState() to manage state.
• Functional Component:
  • Uses useState() hook for state management.

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✅ 3. Lifecycle Methods

• Class Component:
  • Uses lifecycle methods like componentDidMount(), componentDidUpdate(), and componentWillUnmount().
• Functional Component:
  • Uses the useEffect() hook to handle lifecycle behavior.

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✅ 4. this Keyword Usage

• Class Component:
  • Requires usage of this to access props, state, or methods.
• Functional Component:
  • No this keyword needed—simpler and cleaner syntax.

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✅ 5. Performance

• Class Component:
  • Slightly heavier; less performant in some cases (before optimization).
• Functional Component:
  • More lightweight and potentially more performant.

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✅ 6. Hooks Usage

• Class Component:
  • Cannot use React Hooks directly.
• Functional Component:
  • Can fully utilize Hooks like useState, useEffect, useContext, etc.

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✅ 7. Readability & Simplicity

• Class Component:
  • More boilerplate code, especially for binding methods.
• Functional Component:
  • More concise and easier to read and test.

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✅ 8. Community Trend

• Class Component:
  • Still supported but less preferred in modern development.
• Functional Component:
  • The current standard for new React code (especially with Hooks).

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📝 In Summary:

Functional components are now the recommended way to build React components due to their simplicity, hooks support, and better performance patterns, while class components are older and still supported for legacy code.