Podcast
Questions and Answers
What is true about abstract classes in Java?
What is true about abstract classes in Java?
- They cannot contain abstract methods.
- They can be instantiated using the new operator.
- They can be used as a data type. (correct)
- They cannot have constructors.
What is the main difference between an abstract class and a concrete class?
What is the main difference between an abstract class and a concrete class?
- An abstract class can be instantiated, while a concrete class cannot.
- An abstract class is used for multiple inheritance, while a concrete class is used for single inheritance.
- A concrete class can be instantiated, while an abstract class cannot. (correct)
- A concrete class is used for multiple inheritance, while an abstract class is used for single inheritance.
Can a subclass be abstract if its superclass is concrete?
Can a subclass be abstract if its superclass is concrete?
- It depends on the type of superclass.
- It depends on the type of inheritance.
- Yes, it can be abstract. (correct)
- No, it must be concrete.
What is an interface primarily used for in Java?
What is an interface primarily used for in Java?
What is the purpose of constructors in an abstract class?
What is the purpose of constructors in an abstract class?
Can an abstract class contain abstract methods?
Can an abstract class contain abstract methods?
What is the relationship between an abstract class and its subclass?
What is the relationship between an abstract class and its subclass?
What is a characteristic of an interface in Java?
What is a characteristic of an interface in Java?
What is the primary reason for declaring an abstract method in a class?
What is the primary reason for declaring an abstract method in a class?
What happens when a class implements an interface?
What happens when a class implements an interface?
What can an abstract class contain?
What can an abstract class contain?
What is the difference between an interface and an abstract class?
What is the difference between an interface and an abstract class?
Can an abstract class be instantiated?
Can an abstract class be instantiated?
What happens if a subclass of an abstract superclass does not implement all the abstract methods?
What happens if a subclass of an abstract superclass does not implement all the abstract methods?
What is the difference between an abstract class and a concrete class?
What is the difference between an abstract class and a concrete class?
What is the purpose of an abstract class?
What is the purpose of an abstract class?
What is the purpose of defining an interface in Java?
What is the purpose of defining an interface in Java?
What is a key advantage of using interfaces in Java?
What is a key advantage of using interfaces in Java?
