Learn React JS - Full Course for Beginners - Tutorial 2019

Introduction

This tutorial provides a comprehensive step-by-step guide to learning React.js, a popular JavaScript library for building dynamic web applications. By following this guide, you will gain the foundational knowledge necessary to create web applications using React, including concepts like components, state management, and handling events.

Step 1: Understanding React and Its Advantages

• React is a JavaScript library that allows developers to build user interfaces with reusable components.
• Key benefits of using React include:
  • Efficient updates and rendering using the Virtual DOM.
  • Component-based architecture that promotes reusability.
  • Strong community support and a rich ecosystem of tools.

Step 2: Setting Up Your Development Environment

• Install Node.js and npm (Node Package Manager) from the official website.
• Use Create React App to quickly set up a new React project by running:

  npx create-react-app my-app
  cd my-app
  npm start
  

• This command will create a new folder with all necessary files and start the development server.

Step 3: Learning JSX and ReactDOM

• JSX (JavaScript XML) allows you to write HTML-like syntax directly in JavaScript. Example:

  const element = <h1>Hello, world!</h1>;
  

• ReactDOM is the package that enables React components to interact with the DOM. Render your JSX using:

  ReactDOM.render(element, document.getElementById('root'));
  

Step 4: Creating Functional Components

• Functional components are simple JavaScript functions that return JSX. Define a component like this:

  function MyComponent() {
      return <div>Hello, this is my component!</div>;
  }
  

• Use your component in the main application file:

  ReactDOM.render(<MyComponent />, document.getElementById('root'));
  

Step 5: Managing Component Files

• Organize your components by moving them into separate files for better maintainability.
• Create a folder named components, and create individual files for each component.

Step 6: Understanding Parent and Child Components

• Components can be nested, allowing for a parent-child relationship. Pass data to child components using props:

  function ParentComponent() {
      return <ChildComponent message="Hello from Parent!" />;
  }
  
  function ChildComponent(props) {
      return <div>{props.message}</div>;
  }
  

Step 7: Building a Todo App

• Start building a simple Todo Application:
  • Phase 1: Set up the structure and display a list of todos.
  • Phase 2: Add CSS for styling.
  • Phase 3: Implement functionality to add and remove todos.

Step 8: Working with Props

• Props (properties) allow you to pass data between components.
• Create reusable components by accepting props:

  function TodoItem(props) {
      return <li>{props.todoText}</li>;
  }
  

Step 9: Managing State

• Use the useState hook to manage state in functional components.

  import React, { useState } from 'react';
  
  function Example() {
      const [count, setCount] = useState(0);
      return (
          <div>
              <p>You clicked {count} times</p>
              <button onClick={() => setCount(count + 1)}>Click me</button>
          </div>
      );
  }
  

Step 10: Handling Events

• Add event handlers to your components to respond to user actions:

  function handleClick() {
      console.log('Button clicked!');
  }
  
  return <button onClick={handleClick}>Click Me!</button>;
  

Step 11: Lifecycle Methods

• Understand component lifecycle methods in class components to manage side effects:
  • componentDidMount
  • componentDidUpdate
  • componentWillUnmount

Step 12: Conditional Rendering

• Render components conditionally based on state or props:

  {isLoggedIn ? <LogoutButton /> : <LoginButton />}
  

Step 13: Fetching Data from an API

• Use fetch to retrieve data from an API and manage it in your component state.

  useEffect(() => {
      fetch('https://api.example.com/data')
          .then(response => response.json())
          .then(data => setData(data));
  }, []);
  

Step 14: Building Forms

• Create controlled components for forms to handle user input effectively.

Step 15: Capstone Project and Further Learning

• Complete a capstone project, such as a Meme Generator, to apply what you’ve learned.
• Explore additional resources and projects to continue your learning journey.

Conclusion

In this tutorial, you covered the fundamentals of React.js, including component creation, state management, and event handling. By practicing these concepts and building projects, you will gain proficiency in React, opening up opportunities in web development. For further learning, consider exploring advanced topics or contributing to open-source projects.