Claude vs DeepSeek vs Mistral: React

Prompt
react 19 tutorial 2025
ClaudeAnthropic
react 19 tutorial 2025

React 19 Tutorial - 2025 Complete Guide

React 19 brings exciting new features and improvements. Here's a comprehensive tutorial covering the latest updates.

Table of Contents



Installation & Setup

# Create new React 19 project
npx create-react-app@latest my-react19-app
cd my-react19-app
# Or with Vite (recommended)
npm create vite@latest my-react19-app -- --template react
cd my-react19-app
npm install
# Update to React 19
npm install react@19 react-dom@19

New React Compiler

React 19 introduces an automatic compiler that optimizes your components without manual memoization.

// Before React 19 - Manual optimization needed
import { memo, useMemo, useCallback } from 'react';
const ExpensiveComponent = memo(({ data, onUpdate }) => {
  const processedData = useMemo(() => {
    return data.map(item => ({ ...item, processed: true }));
  }, [data]);
  const handleClick = useCallback((id) => {
    onUpdate(id);
  }, [onUpdate]);
  return (
    <div>
      {processedData.map(item => (
        <div key={item.id} onClick={() => handleClick(item.id)}>
          {item.name}
        </div>
      ))}
    </div>
  );
});

// React 19 - Compiler handles optimization automatically
function ExpensiveComponent({ data, onUpdate }) {
  // No need for memo, useMemo, or useCallback
  const processedData = data.map(item => ({ ...item, processed: true }));
  const handleClick = (id) => {
    onUpdate(id);
  };
  return (
    <div>
      {processedData.map(item => (
        <div key={item.id} onClick={() => handleClick(item.id)}>
          {item.name}
        </div>
      ))}
    </div>
  );
}

Actions & useActionState

Actions provide a new way to handle async operations with automatic pending states.

import { useActionState } from 'react';
function UserProfile() {
  const [state, submitAction, isPending] = useActionState(
    async (prevState, formData) => {
      try {
        const response = await fetch('/api/update-profile', {
          method: 'POST',
          body: formData
        });
        
        if (!response.ok) throw new Error('Update failed');
        
        return { 
          success: true, 
          message: 'Profile updated successfully!' 
        };
      } catch (error) {
        return { 
          success: false, 
          message: error.message 
        };
      }
    },
    { success: false, message: '' }
  );
  return (
    <form action={submitAction}>
      <input name="name" placeholder="Your name" required />
      <input name="email" type="email" placeholder="Your email" required />
      
      <button type="submit" disabled={isPending}>
        {isPending ? 'Updating...' : 'Update Profile'}
      </button>
      
      {state.message && (
        <div className={state.success ? 'success' : 'error'}>
          {state.message}
        </div>
      )}
    </form>
  );
}

use() Hook

The new use() hook allows you to read promises and context in a more flexible way.

```jsx
import { use, Suspense } from 'react';

// Promise-based data fetching
async function fetchUserData(userId) {

19:37
DeepSeekDeepSeek
react 19 tutorial 2025

I'll help you create a React 19 tutorial for 2025! React 19 is expected to bring several exciting new features. Here's a comprehensive tutorial covering what we anticipate:

React 19 New Features Overview

1. React Compiler (No More Manual Memoization)

// Before React 19 - manual optimization
const ExpensiveComponent = React.memo(({ data }) => {
  const processedData = useMemo(() => {
    return data.map(item => heavyComputation(item));
  }, [data]);
  
  return <div>{processedData}</div>;
});
// React 19 - Automatic optimization with React Compiler
const ExpensiveComponent = ({ data }) => {
  const processedData = data.map(item => heavyComputation(item));
  
  return <div>{processedData}</div>;
};

2. Actions (Server Actions Integration)

// Server Action (can run on server)
async function updateUser(formData) {
  'use server';
  
  const user = await db.user.update({
    where: { id: formData.get('id') },
    data: { name: formData.get('name') }
  });
  
  return user;
}
// Client Component using Actions
function UserProfile({ userId }) {
  const [isPending, startTransition] = useTransition();
  
  const handleSubmit = async (formData) => {
    startTransition(async () => {
      try {
        const result = await updateUser(formData);
        // Handle success
      } catch (error) {
        // Handle error
      }
    });
  };
  
  return (
    <form action={handleSubmit}>
      <input name="name" defaultValue="John" />
      <button type="submit" disabled={isPending}>
        {isPending ? 'Updating...' : 'Update'}
      </button>
    </form>
  );
}

3. Enhanced use Hook

// Better async handling with use()
function UserProfile({ userId }) {
  const user = use(fetchUser(userId));
  const posts = use(fetchUserPosts(userId));
  
  return (
    <div>
      <h1>{user.name}</h1>
      <div>{posts.map(post => <Post key={post.id} {...post} />)}</div>
    </div>
  );
}
// Using with Context (no more useContext)
function ThemeButton() {
  const theme = use(ThemeContext);
  
  return (
    <button style={{ background: theme.primary }}>
      Themed Button
    </button>
  );
}

4. Asset Loading and Preloading

// Automatic image optimization and loading
function ProductImage({ src, alt }) {
  return (
    <img
      src={src}
      alt={alt}
      loading="lazy"
      // React 19 handles optimization automatically
    />
  );
}
// Preloading resources
function ProductPage({ productId }) {
  use(preloadResource(`/api/products/${productId}`));
  
  return (
    <Suspense fallback={<div>Loading product...</div>}>
      <ProductDetails id={productId} />
    </Suspense>
  );
}

Complete React 19 App Tutorial

Step 1: Setup and Installation

# Create new React app
npx create-react-app@latest my-react19-app
cd my-react19-app
# Install latest React
npm install react@beta react-dom@beta

Step 2: Basic App Structure

// App.jsx
import { Suspense } from 'react';
import { UserProvider } from './context/UserContext';
import UserDashboard from './components/UserDashboard';
function App() {
  return (
    <UserProvider>
      <div className="app">
        <header>
          <h1>React 19 App</h1>
        </header>
        <main>
          <Suspense fallback={<div>Loading app...</div>}>
            <UserDashboard />
          </Suspense>
        </main>
      </div>
    </UserProvider>
  );
}
export default App;

Step 3: Context with use Hook

// context/UserContext.jsx
import { createContext, useState } from 'react';
const UserContext = createContext();
export function UserProvider({ children }) {
  const [user, setUser] = useState(null);
  
  const value = {
    user,
    setUser,
    login: (userData) => setUser(userData),
    logout: () => setUser(null)
  };
  
  return (
    <UserContext.Provider value={value}>
      {children}
    </UserContext.Provider>
  );
}
export default UserContext;

Step 4: Async Component with use()

// components/UserDashboard.jsx
import { use } from 'react';
import UserContext from '../context/UserContext';
import UserProfile from './UserProfile';
import UserPosts from './UserPosts';
function UserDashboard() {
  const { user } = use(UserContext);
  
  if (!user) {
    return <div>Please log in</div>;
  }
  
  return (
    <div className="dashboard">
      <UserProfile userId={user.id} />
      <UserPosts userId={user.id} />
    </div>
  );
}
export default UserDashboard;

Step 5: Server Actions Integration

// actions/userActions.js
'use server';
export async function updateUserProfile(formData) {
  // Simulate API call
  await new Promise(resolve => setTimeout(resolve, 1000));
  
  const updates = {
    name: formData.get('name'),
    email: formData.get('email')
  };
  
  // In real app, save to database
  console.log('Updating user:', updates);
  
  return { success: true, user: updates };
}
export async function uploadUserAvatar(formData) {
  const file = formData.get('avatar');
  
  // Process file upload
  console.log('Uploading avatar:', file.name);
  
  return { success: true, avatarUrl: `/avatars/${file.name}` };
}

Step 6: Form with Actions

// components/UserProfile.jsx
import { useTransition } from 'react';
import { updateUserProfile, uploadUserAvatar } from '../actions/userActions';
function UserProfile({ userId }) {
  const [isPending, startTransition] = useTransition();
  
  const handleProfileUpdate = async (formData) => {
    startTransition(async () => {
      const result = await updateUserProfile(formData);
      
      if (result.success) {
        // Show success message
        console.log('Profile updated successfully');
      }
    });
  };
  
  const handleAvatarUpload = async (formData) => {
    startTransition(async () => {
      const result = await uploadUserAvatar(formData);
      
      if (result.success) {
        // Update UI with new avatar
        console.log('Avatar uploaded successfully');
      }
    });
  };
  
  return (
    <div className="user-profile">
      <form action={handleAvatarUpload}>
        <input type="file" name="avatar" accept="image/*" />
        <button type="submit" disabled={isPending}>
          {isPending ? 'Uploading...' : 'Upload Avatar'}
        </button>
      </form>
      
      <form action={handleProfileUpdate}>
        <input name="name" placeholder="Name" defaultValue="John Doe" />
        <input name="email" type="email" placeholder="Email" defaultValue="john@example.com" />
        <button type="submit" disabled={isPending}>
          {isPending ? 'Updating...' : 'Update Profile'}
        </button>
      </form>
    </div>
  );
}
export default UserProfile;

Step 7: Optimized List Component

// components/UserPosts.jsx
import { use } from 'react';
// React 19 automatically optimizes this - no need for useMemo/React.memo
function UserPosts({ userId }) {
  const posts = use(fetchUserPosts(userId));
  
  return (
    <div className="posts">
      <h2>Recent Posts</h2>
      {posts.map(post => (
        <PostItem 
          key={post.id}
          title={post.title}
          content={post.content}
          date={post.createdAt}
        />
      ))}
    </div>
  );
}
// React Compiler automatically memoizes this component
function PostItem({ title, content, date }) {
  const formattedDate = new Date(date).toLocaleDateString();
  
  return (
    <article className="post">
      <h3>{title}</h3>
      <p>{content}</p>
      <time>{formattedDate}</time>
    </article>
  );
}
// Simulated API call
async function fetchUserPosts(userId) {
  await new Promise(resolve => setTimeout(resolve, 500));
  
  return [
    { id: 1, title: 'First Post', content: 'Hello world!', createdAt: '2024-01-01' },
    { id: 2, title: 'React 19', content: 'Exciting new features!', createdAt: '2024-01-02' }
  ];
}
export default UserPosts;

Key Benefits of React 19


  • Automatic Optimization: React Compiler eliminates manual memoization

  • Simplified Async: use() hook makes async operations more intuitive

3

19:37
MistralMistral AI
react 19 tutorial 2025

As of my knowledge cutoff in October 2023, React 19 has not been released, and there are no official tutorials or documentation available for it. React 18 is the latest stable version as of this time. However, I can provide you with a general guide on how to get started with React, which should be applicable to future versions as well.

Getting Started with React

1. Setting Up Your Environment

First, ensure you have Node.js and npm (Node Package Manager) installed. You can download them from Node.js official website.

2. Creating a New React Project

You can create a new React project using Create React App, a comfortable environment for learning React and a way to start building a new single-page application in React.

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

This will create a new directory called my-app and start the development server.

3. Understanding the Project Structure

A typical React project created with Create React App has the following structure:

my-app/
├── node_modules/
├── public/
│   ├── index.html
│   └── ...
├── src/
│   ├── App.css
│   ├── App.js
│   ├── App.test.js
│   ├── index.css
│   ├── index.js
│   ├── logo.svg
│   └── ...
├── .gitignore
├── package.json
├── README.md
└── ...

4. Writing Your First Component

Open src/App.js and modify it to create a simple component:

import React from 'react';
import './App.css';
function App() {
  return (
    <div className="App">
      <header className="App-header">
        <h1>Welcome to React!</h1>
      </header>
    </div>
  );
}
export default App;

5. Running Your Application

If you haven't already, start the development server:

npm start

Open your browser and navigate to http://localhost:3000. You should see your "Welcome to React!" message.

6. Adding State and Props

React components can have state and props. Let's add a simple counter component with state:

import React, { useState } from 'react';
import './App.css';
function Counter() {
  const [count, setCount] = useState(0);
  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}
function App() {
  return (
    <div className="App">
      <header className="App-header">
        <h1>Welcome to React!</h1>
        <Counter />
      </header>
    </div>
  );
}
export default App;

7. Adding More Components

You can create more components and import them into your App.js file. For example, create a new file src/components/Greeting.js:

import React from 'react';
function Greeting({ name }) {
  return <h2>Hello, {name}!</h2>;
}
export default Greeting;

Then, import and use this component in App.js:

import React from 'react';
import './App.css';
import Greeting from './components/Greeting';
function App() {
  return (
    <div className="App">
      <header className="App-header">
        <h1>Welcome to React!</h1>
        <Greeting name="World" />
        <Counter />
      </header>
    </div>
  );
}
export default App;

8. Styling Your Components

You can style your components using CSS. Create a new file src/components/Greeting.css:

h2 {
  color: blue;
}

Then, import this CSS file in Greeting.js:

import React from 'react';
import './Greeting.css';
function Greeting({ name }) {
  return <h2>Hello, {name}!</h2>;
}
export default Greeting;

9. Deploying Your Application

To deploy your application, you can use services like Vercel, Netlify, or GitHub Pages. For example, to deploy with Vercel:

  • Install the Vercel CLI:


npm install -g vercel

  • Deploy your project:


vercel

Follow the prompts to deploy your application.

Conclusion

This guide covers the basics of setting up a React project, creating components, managing state, and deploying your application. As React evolves, the core concepts will likely remain the same, but new features and best practices may emerge. Always refer to the official React documentation for the most up-to-date information.

19:37

💡 Try this comparison yourself:Compare AI models side-by-side on SNEOS

Analysis

This comparison demonstrates the different approaches each AI model takes when responding to the same prompt. Here are the key differences observed:

Response Characteristics

Claude: Provides a direct response with 41 sentences.

DeepSeek: Provides a detailed response with 80 sentences.

Mistral: Provides a direct response with 74 sentences.

Key Takeaways

  • Each model brings unique strengths to this type of query
  • Response styles vary significantly between models
  • Consider your specific use case when choosing between these models

Try This Comparison Yourself

Want to test these models with your own prompts? Visit SNEOS.com to compare AI responses side-by-side in real-time.

This comparison was generated using the SNEOS AI Comparison ToolPublished: October 01, 2025 | Models: Claude, DeepSeek, Mistral