Events play a fundamental role in React applications, as they allow user interactions that can trigger state changes. In this section, we will learn how to handle events and how to update the state in response to these events in both functional and class components.

Events in React

React normalizes native browser events to ensure events behave consistently across all browsers. To handle events in React, camelCase event names are used, and functions are passed as event handlers.

Basic Syntax:

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Event Handling in Functional Components

In functional components, events are handled using regular functions or arrow functions, and state updates are performed through hooks such as useState.

Simple Example:

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Event Handling in Class Components

In class components, events are typically handled with instance methods. It is necessary to bind these methods to ensure that this refers to the correct component.

Simple Example:

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Binding Methods in Class Components

It is important to remember that in class components, you must bind event handler methods to ensure that this points to the appropriate component.

Binding Methods:

1. In the Constructor:

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2. Arrow Function as Class Property:

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Common Events in React

onClick

The onClick event is triggered when an element is clicked.

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onChange

The onChange event is commonly used with inputs to capture changes in values.

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onSubmit

The onSubmit event is triggered when a form is submitted.

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Practical Example: Registration Form

Functional Component:

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Class Component:

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Explanatory Image

Event handling and state updating are key pieces to creating interactive and dynamic React applications. In the next section, we will learn about Passing State Between Components with Props, which is crucial for sharing data and coordinating actions between different parts of a React application.