Difference between pureComponent and component in React

This is a short tutorial that explains the difference between PureComponent and Component.

Normal Component example

Normal components are created in every application by extending React. component for Class components.

• Created a component using the class keyword
• Extends React.component
• It has callback lifecycle methods like componentWillMount etc.
• Also can add event handler methods, For example, Adding a button and its event handler click event
• The state can be Scalar types like Integer, String, and nested data structures.

import React, { Component } from 'react';
import PropTypes from 'prop-types';

class NormalComponent extends Component {
    constructor(props) {
        super(props);

    }

    componentWillMount() {

    }

    componentDidMount() {

    }

    componentWillReceiveProps(nextProps) {

    }

    shouldComponentUpdate(nextProps, nextState) {

    }

    componentWillUpdate(nextProps, nextState) {

    }

    componentDidUpdate(prevProps, prevState) {

    }

    componentWillUnmount() {

    }

    render() {
        return (
            <div>

            </div>
        );
    }
}

NormalComponent.propTypes = {

};

export default NormalComponent;

React PureComponent example

PureComponent is created by extending React.PureComponent with class keyword

• Created components with class keyword
• Extends React.PureComponent
• No callback or life cycle methods
• State can be scalar types only

import React, { PureComponent } from 'react'
export default Class PureComponentExample  extends React.PureComponent{
       render() {
        return (
            <div>

            </div>
        );
    }
}

Difference between pure component and normal Component in react

Normal React component does not call shouldComponentUpdate by default.

Pure components call shouldComponentUpdate and check shallow comparison logic to render a component or not, that means PureComponent is used when there are many changes in state or props

If your parent component is pure, and all children’s components are compulsory to be pure components.

Conclusion, When there are heavy state/prop changes in components, use Normal Component.