Mastering Modern JavaScript

JavaScript continues to evolve with new features and best practices. In this guide, we'll explore advanced concepts and techniques that every modern JavaScript developer should know.

1. Modern Async Programming

Master the latest async programming patterns:

// Using async/await with Promise.all
async function fetchUserData() {
    try {
        const [profile, posts, analytics] = await Promise.all([
            fetchProfile(),
            fetchPosts(),
            fetchAnalytics()
        ]);
        return { profile, posts, analytics };
    } catch (error) {
        console.error('Error fetching data:', error);
    }
}

2. Advanced Array Methods

Powerful array manipulation techniques:

// Modern array methods
const users = [/* user data */];

const activeAdmins = users
    .filter(user => user.isActive)
    .map(user => user.role === 'admin')
    .reduce((acc, user) => {
        acc[user.id] = user;
        return acc;
    }, {});

3. ES2025 Features

Latest JavaScript features you should know:

• Pattern Matching - Elegant data extraction
• Decorators - Enhanced class customization
• Pipeline Operator - Functional composition

4. Performance Optimization

// Memory-efficient code
const heavyOperation = (() => {
    const cache = new WeakMap();
    
    return (obj) => {
        if (cache.has(obj)) {
            return cache.get(obj);
        }
        const result = /* expensive computation */;
        cache.set(obj, result);
        return result;
    };
})();

5. Testing Best Practices

Modern testing approaches:

// Using modern testing patterns
describe('UserService', () => {
    it('should handle authentication', async () => {
        const service = new UserService();
        const result = await service.authenticate({
            username: 'test',
            password: 'pass'
        });
        expect(result).toMatchSnapshot();
    });
});