聪明的鸡腿

// 异步函数示例
async function fetchUserData() {
    try {
        const response = await fetch('https://api.example.com/users');
        const data = await response.json();
        return data;
    } catch (error) {
        console.error('获取用户数据失败:', error);
    }
}

// 类定义示例
class User {
    constructor(name, age) {
        this.name = name;
        this.age = age;
    }

    sayHello() {
        return `你好，我是 ${this.name}，今年 ${this.age} 岁`;
    }
}
        

# 装饰器示例
def timer(func):
    def wrapper(*args, **kwargs):
        start = time.time()
        result = func(*args, **kwargs)
        end = time.time()
        print(f"函数 {func.__name__} 执行时间: {end - start}秒")
        return result
    return wrapper

@timer
def process_data(data):
    return [x * 2 for x in data if x > 0]

# 类继承示例
class Animal:
    def __init__(self, name):
        self.name = name
    
    def speak(self):
        pass

class Dog(Animal):
    def speak(self):
        return f"{self.name} 说：汪汪！"
        

interface User {
    id: number;
    name: string;
    age?: number;
}

type UserRole = 'admin' | 'user' | 'guest';

class UserService {
    private users: Map = new Map();

    public addUser(user: User): void {
        this.users.set(user.id, user);
    }

    public getUser(id: number): User | undefined {
        return this.users.get(id);
    }
}

function processUser(user: T): T {
    console.log(`处理用户: ${user.name}`);
    return user;
}
        

public class StreamExample {
    public static void main(String[] args) {
        List names = Arrays.asList("Alice", "Bob", "Charlie");
        
        names.stream()
            .filter(name -> name.length() > 3)
            .map(String::toUpperCase)
            .sorted()
            .forEach(System.out::println);
    }
}

@Service
public class UserService {
    @Autowired
    private UserRepository userRepository;

    @Transactional
    public User createUser(UserDTO dto) {
        User user = new User();
        user.setName(dto.getName());
        user.setEmail(dto.getEmail());
        return userRepository.save(user);
    }
}