Understanding Inheritance in Java

What is single inheritance in Java?

• Single inheritance allows a class to inherit from one superclass in Java.

• Single inheritance allows a class to inherit from multiple superclasses in Java.

• Single inheritance is a feature that allows a class to implement multiple interfaces in Java.

• Single inheritance means a class cannot inherit any properties from its superclass in Java.

Can a class in Java inherit from multiple classes?

• Java supports multiple inheritance through interfaces.

• No, a class in Java cannot inherit from multiple classes.

• Yes, a class in Java can inherit from multiple classes.

• A class in Java can implement multiple classes.

What is method overriding and how is it implemented?

• Method overriding is a way to create new methods in a class without affecting existing ones.

• Method overriding is a feature that allows multiple classes to share the same method name without any implementation.

• Method overriding is a feature in object-oriented programming that allows a subclass to provide a specific implementation of a method that is already defined in its superclass.

• Method overriding is when a superclass changes its own method implementation.

What are the rules for method overriding in Java?

• The method must have a different name than the original.

• Static methods can be overridden in subclasses.

• The rules for method overriding in Java include matching method name, parameters, and return type, not being more restrictive in access modifiers, and not overriding static, final, or private methods.

• Overriding methods can only be public.

What is an abstract class in Java?

• An abstract class must contain only concrete methods.

• An abstract class can be instantiated directly.

• An abstract class cannot have any fields or properties.

• An abstract class in Java is a class that cannot be instantiated and may contain abstract methods that must be implemented by subclasses.

How do you declare an abstract method in Java?

• public abstract void methodName();

• public void methodName();

• abstract void methodName(){};

• void abstract methodName();

What is the difference between an abstract class and an interface?

• An abstract class cannot have any methods, while an interface can.

• An abstract class can only be instantiated, while an interface cannot be instantiated.

• An abstract class can implement multiple interfaces, while an interface cannot implement any classes.

• An abstract class can have implemented methods and state, while an interface cannot.

How do interfaces support multiple inheritance in Java?

• Interfaces do not allow any form of inheritance in Java.

• Classes can inherit from multiple classes directly in Java.

• Interfaces allow a class to implement multiple types, enabling multiple inheritance in Java.

• Interfaces can only be used for single inheritance in Java.

What are default methods in interfaces?

• Default methods are static methods in interfaces.

• Default methods are methods in interfaces that have a default implementation, allowing classes to inherit them without overriding.

• Default methods are only applicable in abstract classes.

• Default methods cannot be overridden by implementing classes.

Can an interface extend another interface in Java?

• Interfaces in Java cannot inherit from other interfaces.

• An interface can only implement another interface in Java.

• No, an interface cannot extend another interface in Java.

• Yes, an interface can extend another interface in Java.