C# Sealed Class vs Java Final Class: Key Differences Explained

What are the differences between C# sealed classes and Java final classes?

C# and Java, two popular programming languages, implement class restriction features to control inheritance and improve security. In C#, the `sealed` keyword prevents a class from being inherited further, while in Java, the `final` keyword fulfills a similar role. This article explores the differences, uses, and implications of both classes.

// C# example of a sealed class
public sealed class SealedClass {
    public void Display() {
        Console.WriteLine("This is a sealed class.");
    }
}

// Java example of a final class
public final class FinalClass {
    public void show() {
        System.out.println("This is a final class.");
    }
}

Causes

• C# uses the `sealed` keyword to prevent further inheritance, ensuring that the class cannot be subclassed.
• Java employs the `final` keyword for classes and methods, indicating that they cannot be extended or overridden.

Solutions

• Use `sealed` in C# when you want to restrict a class from being inherited, improving performance and maintaining encapsulation.
• Use `final` in Java to prevent any subclassing or overriding, ensuring consistent behavior of a class.

Mistake: Forgetting to mark derived classes correctly after sealing in C#.

Solution: Make sure to clearly document your sealed classes and communicate the intention of restricting further inheritance.

Mistake: Misunderstanding the scope of final in Java, thinking it doesn't affect methods as well.

Solution: Recognize that both methods and classes can be marked as final and understand the resulting implications.