Difference between declarative and imperative in React.js

React.js is a popular JavaScript library used for building user interfaces. It provides a way to create reusable UI components and efficiently update the UI when the underlying data changes. When working with React, you may come across the terms “declarative” and “imperative” programming. In this article, we will explore the difference between these two approaches in the context of React.js.

Declarative Programming

In declarative programming, you describe what you want to achieve, and the framework takes care of the implementation details. In React.js, you define the desired UI state based on the current data, and React automatically updates the UI to reflect that state.

Declarative programming in React.js involves creating reusable components that encapsulate their own state and behavior. These components are composed together to build complex UIs. When the underlying data changes, React efficiently updates only the affected components, minimizing the need for manual DOM manipulation.

Here’s an example of declarative programming in React.js:

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

  return (
    

      
Count: {count}
       setCount(count + 1)}>Increment
    
  );
}

In the above code snippet, we declare the desired UI state using the useState hook. The UI is updated automatically when the count state changes, thanks to React’s declarative nature.

Imperative Programming

In imperative programming, you explicitly define the steps to achieve a desired outcome. You manually manipulate the DOM and update the UI based on the current data and user actions.

While React.js promotes a declarative approach, there are situations where imperative programming is necessary. For example, when integrating with third-party libraries or working with low-level DOM APIs.

Here’s an example of imperative programming in React.js:

function App() {
  const buttonRef = useRef(null);

  const handleClick = () => {
    const button = buttonRef.current;
    if (button) {
      button.style.backgroundColor = 'red';
    }
  };

  return (
    

      Change Color
    
  );
}

In the above code snippet, we use the useRef hook to create a reference to the button element. When the button is clicked, we manually update its background color using imperative DOM manipulation.

Conclusion

Declarative programming is the preferred approach in React.js, as it allows for easier code maintenance, better reusability, and efficient UI updates. However, there are cases where imperative programming is necessary, such as when interacting with external libraries or performing low-level DOM operations.

Understanding the difference between declarative and imperative programming in React.js is crucial for writing clean and efficient code. By leveraging React’s declarative nature, you can build complex UIs with ease and focus on the desired outcome rather than the implementation details.

That’s all for this article! We hope you found it helpful in understanding the difference between declarative and imperative programming in React.js.

Happy coding!