Java Interview Guide : 200+ Interview Questions and Answers - Inheritance, Method overloading and Method overriding

The video tutorial covers the concept of inheritance in Java, including method overloading and overriding. It explains how inheritance allows for code reuse and the creation of a class hierarchy. The tutorial also discusses reference variables and the limitations of multiple inheritance in Java. Examples from the Java API, such as ArrayList and HashMap, are used to illustrate these concepts.

What is the primary purpose of inheritance in object-oriented programming?

• To enable a class to inherit properties and methods from another class

• To create a new class without any methods or properties

• To restrict access to certain methods and properties

• To allow a class to have multiple parent classes

In the Java library, which class does ArrayList directly extend?

• HashMap

• LinkedList

• AbstractList

• AbstractCollection

What is method overloading?

• Defining a method with different return types

• Defining a method with the same name in different classes

• Defining multiple methods with the same name but different parameters

• Defining a method in a subclass with the same name and parameters as in the superclass

Which of the following is an example of method overloading?

• A method with the same name and parameters in a subclass

• A method with the same name but different parameters in the same class

• A method with a different name but same parameters

• A method with the same name and parameters in a different class

What is method overriding?

• Using a method from a different class

• Providing a specific implementation for a method already defined in the superclass

• Creating a new method with the same name but different parameters

• Defining a method with a different name in the subclass

Which method is overridden in the HashMap class?

• remove()

• size()

• add()

• clear()

Can a superclass reference variable hold an object of its subclass?

• No, it cannot

• No, unless the subclass is final

• Yes, but only if the subclass is abstract

• Yes, it can

Why does Java not support multiple inheritance?

• It is supported but not recommended

• It is not needed in object-oriented programming

• It leads to complex and ambiguous programs

• Java supports it through interfaces

What is the result of trying to extend two classes in Java?

• The program will compile successfully

• A runtime error will occur

• A compilation error will occur

• The program will run but with warnings

In Java, what is allowed instead of multiple inheritance?

• None of the above

• Both A and B

• Multiple interfaces

• Inheritance hierarchy