Sealed Classes (introduced in Java 15)

 Sealed Classes (introduced in Java 15)

Sealed classes restrict the inheritance hierarchy of a class, allowing you to specify which classes can extend it. This promotes better control and helps prevent unintended subclassing. Here's an example:

public sealed class Shape permits Circle, Rectangle {

    // Common shape properties and methods

}

public final class Circle extends Shape {

    // Circle-specific properties and methods

}

public final class Rectangle extends Shape {

    // Rectangle-specific properties and methods

}