Event Handling

Event handling in React components is crucial for defining the user interface's response to user interactions, such as clicking a button or submitting a form.

In usual HTML, we use the onclick attribute of the button element to specify a function that handles the click event. React is similar, except the attribute name is in camelCase: onClick.

In functional components, the functions that handle events are usually created as inline functions inside the component's function.

Following is a very simple example of event handling:

In the above code, handleClick is the inline function that sets the innerHTML of the button to Clicked! when it's clicked.

It is important to note that we can use an external function to handle events as well:

However, the common convention is to use inline functions due to some of their advantages and neatness. Since inline functions have a local scope, we don't have to worry about duplicate naming.

Apart from that, accessing component data from the inline functions is easier, especially while using hooks which we will explore in the later chapters.

We can also directly embed inline functions into expressions to make the code shorter:

We can also pass extra arguments to event handlers using the following method:

Everything was clear?

Section 5. Chapter 5

Course Content

Introduction to React

1. Getting Started: ES6

Why React?Node.js and npm ES6 Variables ES6 Arrow Functions ES6 Map Method ES6 Destructuring ES6 Spread Operator ES6 Ternary Operator

2. Getting Started: JSX

JSX Introduction JSX Variables & Nested Elements JSX Embedding Expressions JSX Specifying Attributes Getting Started with React

3. React in Practice

Getting familiar with JSX Writing more Complex Elements using JSX Creating a React-Based Project Structure of a React Project

4. React Components

Introduction to Components Functional Components Creating React Components Importing Components

5. Controlling Data & Content

Passing Data into Components Conditional Rendering Loop Based Rendering Keys in Lists Event Handling Creating a TODO Application

6. Hooks

Introduction to Hooks Using the State Hook The Effect Hook Rules of Using Hooks Creating Custom Hooks Fixing the Todo Application

7. React Router

Introduction to React Router Route-Based Rendering Creating Navigation Bars Using Params