What are Pure Components in React

ReactJS has provided us with a Pure Component. If we extend a class with Pure Component, there is no need for the shouldComponentUpdate() lifecycle method. ReactJS Pure Component Class compares the current state and props with new props and states to decide whether the React component should re-render itself or not.

In simple words, If the previous value of the state or props and the new value of the state or props are the same, the component will not re-render itself. Pure Components restricts the re-rendering when there is no use for re-rendering of the component. Pure Components are Class Components that extend React.PureComponent

Example

This example demonstrates the creation of Pure Components. 

Javascript
import React from "react";

export default class Test extends React.PureComponent {
    render() {
        return <h1>Welcome to w3wiki</h1>;
    }
}

Output :

ReactJS Pure Components

Generally, In ReactJS, we use the shouldComponentUpdate() Lifecycle method to customize the default behavior and implement it when the React component should re-render or update itself.

When working with React pure components, we can utilize their behavior to optimize behavior as pure components automatically handle the shouldComponentUpdate() method and we don’t need to explicitly implement it.

In this article, we will learn what is Pure component in React, and its key points with examples.

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Prerequisites

React JS ComponentsReact JS Components – Set 2...

What are Pure Components in React

ReactJS has provided us with a Pure Component. If we extend a class with Pure Component, there is no need for the shouldComponentUpdate() lifecycle method. ReactJS Pure Component Class compares the current state and props with new props and states to decide whether the React component should re-render itself or not....

Pure Components Key Points

Some key points to remember about Pure Components are:...

Pure Components Advantage

Extending React Class Components with Pure Components ensures the higher performance of the Component and ultimately makes your application faster....

Important Considerations

There is also a possibility that these State and Props objects contain nested data structure then Pure Component’s implemented shouldComponentUpdate will return false and will not update the whole subtree of Children of this Class Component. So in Pure Component, the nested data structure doesn’t work properly....

Conclusion

Pure components improve the performance and speed in React by avoiding unnecessary re-renders. They perform shallow comparisons of props and state, resulting in improved performance and simplified code writing....