### 4. Switch Expressions (Java 14)

String dayType = switch (day) {
    case "Mon", "Tue", "Wed", "Thu", "Fri" -> "Weekday";
    case "Sat", "Sun" -> "Weekend";
    default -> throw new IllegalArgumentException();
};

---

## 🔹 Practical Example: Employee Processing

public class Employee {
    private String name;
    private String department;
    private double salary;
    // Constructor, getters
}

List<Employee> employees = // ... initialized list

// Stream processing example
Map<String, Double> avgSalaryByDept = employees.stream()
    .collect(Collectors.groupingBy(
        Employee::getDepartment,
        Collectors.averagingDouble(Employee::getSalary)
    ));

// Modern Java features
List<String> highEarners = employees.stream()
    .filter(e -> e.salary() > 100000)
    .map(Employee::name)
    .sorted()
    .toList();  // Java 16+ toList()

System.out.println(avgSalaryByDept);
System.out.println(highEarners);

---

## 🔹 Best Practices
1. Prefer immutability with records and unmodifiable collections
2. Use Optional instead of null checks
3. Favor functional style with streams for data processing
4. Keep lambdas short and readable
5. Adopt modern features gradually in existing codebases

---

### 🎉 Congratulations!
You've completed our 10-part Java series! Here's what we covered:
1. Java Basics
2. Operators & Control Flow
3. Methods & Functions
4. OOP Concepts
5. Inheritance & Polymorphism
6. Interfaces & Abstract Classes
7. Packages & Access Modifiers
8. Exception Handling
9. Collections Framework
10. Streams & Modern Features

#JavaProgramming #CompleteCourse #ModernJava 🚀

What's next?
➡️ Build real projects
➡️ Explore frameworks (Spring, Jakarta EE)
➡️ Learn design patterns
➡️ Contribute to open source

Happy coding! 👨‍💻👩‍💻