Polymorphism in Object-Oriented Programming: Definition and Types

Question 1

Which of the following scenarios would NOT demonstrate polymorphism?

Accepted Answer

A method can have different parameter types but the same name in different subclasses.

Answer

A superclass reference variable can refer to a subclass object.

Answer

A method can have the same name but different implementations in different subclasses.

Answer

A variable can hold objects of different classes that share a common superclass.

Question 2

In the context of polymorphism, what does method overloading refer to?

Accepted Answer

Using the same method name with different parameter lists in the same class.

Answer

Using the same method name with different return types in the same class.

Answer

Using different method names with the same functionality in different subclasses.

Answer

Using different method names with different parameter lists in different subclasses.

Question 3

Which of the following is an example of method overriding?

Accepted Answer

Defining a method with the same name and signature in a subclass as in its superclass but with a different implementation.

Answer

Defining a method with the same name but different signature in a subclass as in its superclass.

Answer

Defining a method with a different name but same signature in a subclass as in its superclass.

Answer

Defining a method with a different name and different signature in a subclass as in its superclass.

Question 4

What is the purpose of the @Override annotation in Java when overriding methods?

Accepted Answer

It ensures that the method is actually overriding a method in the parent class.

Answer

It improves code readability and documentation.

Answer

It allows for more efficient code execution.

Answer

It is optional and does not affect the functionality of the code.

Question 5

What is the main purpose of using a super() call in a constructor?

Accepted Answer

To invoke the constructor of the parent class

Answer

To initialize instance variables

Answer

To call helper methods from the parent class

Answer

To pass arguments to the parent class constructor

Question 6

In object-oriented programming, polymorphism refers to:

Accepted Answer

The ability of an object to behave differently based on its implementation

Answer

The process of creating multiple objects from a single class

Answer

The use of inheritance to create different versions of a method

Answer

The ability of an object to be instantiated from multiple classes

Question 7

Which of the following is an example of method overloading?

Accepted Answer

Creating multiple versions of a method with the same name but different argument types in the same class

Answer

Defining multiple constructors with different parameter lists in the same class

Answer

Creating a child class that overrides a method from its parent class

Answer

Creating an abstract class with a method that has no implementation

Question 8

What is the main purpose of using the @Override annotation in Java when overriding a method?

Accepted Answer

To ensure that the method is actually overriding a method from a superclass

Answer

To enhance code readability and documentation

Answer

To improve performance of the overridden method

Answer

To prevent accidental overriding of methods

Question 9

Method overloading refers to:

Accepted Answer

Having multiple methods with the same name but different parameters

Answer

Having multiple methods with the same name and parameters but different return types

Answer

Having multiple classes with the same method name

Answer

Having multiple objects with the same method name

Question 10

Polymorphism is achieved through:

Accepted Answer

Inheritance and method overriding

Answer

Inheritance and method overloading

Answer

Encapsulation and method overloading

Answer

Encapsulation and method overriding

Question 11

Which of the following statements best describes the relationship between a parent class and its child class in terms of polymorphism?

Accepted Answer

The child class inherits from the parent class and can override its methods.

Answer

The parent class inherits from the child class and can overload its methods.

Answer

The child class inherits from the parent class and can overload its methods.

Answer

The parent class inherits from the child class and can override its methods.

Question 12

What is the purpose of using the @Override annotation in Java?

Accepted Answer

To indicate that a method overrides a method in the parent class

Answer

To indicate that a method is overloaded in the child class

Answer

To prevent a method from being inherited in the child class

Answer

To mark a method as final and prevent it from being overridden

Question 13

Which of the following is a characteristic of a polymorphic method?

Accepted Answer

It can have different implementations in different subclasses

Answer

It must have the same name and parameters in all subclasses

Answer

It must be declared as final in the parent class

Answer

It cannot be inherited by subclasses

Question 14

Can a static method be overridden in a subclass?

Accepted Answer

No

Answer

Yes

Answer

Only if the subclass is declared final

Answer

Only if the parent class is declared abstract

Question 15

How does method overriding affect the behavior of inherited methods, and what are its implications for designing class hierarchies?

Accepted Answer

Overriding methods in subclasses modify the behavior defined by inherited methods, enabling specialized implementations.

Answer

Overriding methods are independent of inherited methods and have no impact on their behavior.

Answer

Overriding methods can only be defined in parent classes, not in child classes.

Question 16

Which of the following is NOT a type of polymorphism in object-oriented programming?

Accepted Answer

Covariant return types

Answer

Method overloading

Answer

Method overriding

Answer

Constructor overloading

Question 17

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

Accepted Answer

To provide multiple implementations of the same operation with different parameter lists

Answer

To allow a method to have multiple return types

Answer

To reduce the number of methods in a class by combining similar functionality

Answer

To improve code readability by using descriptive method names

Question 18

Which of the following best defines method overloading?

Accepted Answer

Having multiple methods with the same name but different parameters in the same class

Answer

Having multiple methods with the same name and parameters but in different classes

Answer

Having multiple methods with different names but the same parameters in the same class

Answer

Having multiple methods with the same name but different return types in the same class

Question 19

Which statement accurately describes polymorphism?

Accepted Answer

It allows objects of different classes to be treated uniformly as objects of a common superclass or interface.

Answer

It is implemented exclusively through function overloading.

Answer

It promotes code reusability but not flexibility.

Answer

It is not supported in all object-oriented programming languages.

Question 20

Which of the following is an example of method overriding?

Accepted Answer

Defining two methods with the same name and parameter list in a subclass and superclass

Answer

Defining two methods with the same name but different parameter lists in the same class

Answer

Defining two methods with different names but the same parameter list in the same class

Answer

Defining two methods with the same name and parameter list in different classes

Question 21

What is the primary purpose of using the @Override annotation?

Accepted Answer

To indicate that a method overrides a method from a superclass

Answer

To prevent a method from being overridden in subclasses

Answer

To ensure that a method is implemented in all subclasses

Answer

To automatically generate overridden methods

Question 22

Which of the following is an example of a polymorphic variable declaration?

Accepted Answer

Animal animal = new Dog();

Answer

Dog dog = new Animal();

Answer

String name = "John";

Answer

int number = 10;

Question 23

What occurs when a subclass overrides a superclass method with a private access modifier?

Accepted Answer

The overridden method in the subclass becomes private and is only accessible within the subclass.

Answer

The overridden method in the subclass is not accessible from either the subclass or the superclass.

Answer

The overridden method in the subclass overrides the superclass method and becomes accessible outside the subclass.

Answer

The overridden method in the subclass is duplicated, and both the subclass and superclass have their own versions.

Question 24

Which of the following is NOT an advantage of polymorphism?

Accepted Answer

Improved performance

Answer

Code reusability

Answer

Flexibility

Answer

Reduced code complexity

Question 25

What is the term used to describe the ability of objects from different classes to respond to the same message with distinct behaviors?

Accepted Answer

Polymorphism

Answer

Encapsulation

Answer

Inheritance

Answer

Abstraction

Question 26

What is the definition of method overriding?

Accepted Answer

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

Answer

Invoking a method from a superclass within a subclass method

Answer

Altering the behavior of a method in a subclass without changing its signature

Answer

Overloading a method with different parameters in a subclass

Question 27

True or False: Polymorphism enables objects to maintain a uniform interface despite variations in their underlying implementations.

Accepted Answer

True

Answer

False

Question 28

How does dynamic binding contribute to polymorphism?

Accepted Answer

It determines the specific method to be invoked at runtime based on the actual object type

Answer

It ensures that the method with the most specialized implementation is always executed

Answer

It enables objects of different classes to respond to the same message with diverse behaviors

Answer

It simplifies the process of overriding methods

Question 29

What is the term for defining identically-named methods in subclasses of a hierarchy?

Accepted Answer

Method Overriding

Answer

Method Overloading

Answer

Polymorphism

Answer

Inheritance

Question 30

Which of the following is a valid example of method overloading?

Accepted Answer

Two methods with the same name but different parameters

Answer

Two methods with the same name and parameters in different classes

Answer

Two methods with different names and parameters

Answer

Two methods with different names but the same parameters

Question 31

What principle allows objects of different classes to be treated as objects of a common superclass?

Accepted Answer

Subtype Polymorphism

Answer

Overriding

Answer

Overloading

Answer

Encapsulation

Question 32

Which of the following could be a potential limitation of polymorphism?

Accepted Answer

Reduced code readability

Answer

Increased runtime performance

Answer

Enhanced debugging possibilities

Answer

Improved code maintenance

Question 33

When a method is called on an overridden object, what occurs?

Accepted Answer

The method defined in the subclass is executed.

Answer

The method defined in the superclass is executed.

Answer

A compile-time error is generated.

Answer

The program terminates abnormally.

Question 34

Which of the following is an example of method overriding?

Accepted Answer

Two methods with the same name and parameters in different subclasses

Answer

Two methods with the same name but different parameters in the same class

Answer

Two methods with different names and parameters in the same class

Answer

Two methods with different names and parameters in different subclasses

Question 35

Which characteristic is central to the concept of polymorphism?

Accepted Answer

Objects behave differently based on their class

Answer

Code is simplified by eliminating conditional statements

Answer

Code readability and maintainability are enhanced

Answer

Inheritance is no longer required

Question 36

How does method overriding relate to polymorphism?

Accepted Answer

Method overriding is a type of polymorphism.

Answer

Method overriding blocks polymorphism.

Answer

Polymorphism is a type of method overriding.

Answer

Method overriding and polymorphism are separate ideas.

Question 37

When an overridden method is called on an object of a subclass, which method is executed?

Accepted Answer

Method defined in the class of the object's actual type

Answer

Method defined in the superclass

Answer

Method defined in the subclass

Answer

Method defined in the class of the object's declared type

Question 38

What is the primary purpose of the @Override annotation?

Accepted Answer

To indicate that a method is overriding a method in a superclass.

Answer

To indicate that a method is implementing a method in an interface.

Answer

To indicate that a method is abstract.

Answer

To indicate that a method is static.

Question 39

Which of the following is NOT a type of polymorphism?

Accepted Answer

Contravariance

Answer

Method overloading

Answer

Method overriding

Answer

Constructor overloading

Question 40

What is the primary benefit of polymorphism?

Accepted Answer

Code reusability

Answer

Improved readability

Answer

Enhanced performance

Answer

Reduced memory usage

Question 41

What is the purpose of the @Override annotation?

Accepted Answer

To indicate that a subclass method overrides a parent method

Answer

To prevent a subclass method from overriding a parent method

Answer

To mark a method as polymorphic

Answer

To ensure that a method is called from the parent class

Question 42

Can a static method be overridden in a derived class?

Accepted Answer

No

Answer

Only if it is declared as abstract in the parent class

Answer

Yes

Answer

Only if it is declared as final in the parent class

Question 43

Which of the following is a fundamental characteristic of polymorphism?

Accepted Answer

It allows objects of different classes to be treated as objects of a common superclass or interface.

Answer

It is only possible with abstract classes.

Answer

It is a programming technique used to redefine a method in a derived class.

Question 44

In method overriding, the method in the derived class:

Accepted Answer

Must have the same name, parameter list, and return type as the method in the base class.

Answer

Can have a different number of parameters than the method in the base class.

Answer

Can have a different return type than the method in the base class.

Question 45

Which of the following is a potential drawback of polymorphism?

Accepted Answer

Increased code complexity due to the need for dynamic binding.

Answer

Flexibility

Answer

Code reusability

Answer

Extensibility

Question 46

What is the role of dynamic binding in polymorphism?

Accepted Answer

It determines which method of an overridden set to invoke at runtime, based on the actual object type.

Answer

It prevents methods from being overridden in derived classes.

Answer

It allows methods to be called without specifying their parameters.

Question 47

Identify a potential disadvantage of polymorphism:

Accepted Answer

Potentially increased runtime complexity due to method resolution overhead

Answer

Enhanced code readability

Answer

Improved code reusability

Question 48

Which of the following statements about method overloading is incorrect?

Accepted Answer

Overloaded methods must have different return types.

Answer

Overloaded methods must have the same method name.

Answer

Overloaded methods can have different parameter lists.

Question 49

In Java, what keyword is used to indicate that a method overrides a method in the superclass?

Accepted Answer

Override

Answer

Virtual

Answer

Abstract

Question 50

Consider the following code snippet:

`class Pet { public void speak() { System.out.println("Pet speaks"); } } class Dog extends Pet { @Override public void speak() { System.out.println("Dog barks"); } }`

What is the output when the following statement is executed: Dog dog = new Dog(); dog.speak();

Accepted Answer

Dog barks

Answer

NullPointerException

Answer

Compilation error

Answer

Pet speaks

Question 51

Which of the following is a key advantage of polymorphism?

Accepted Answer

Increased code reusability through the ability to treat objects of different subclasses as objects of their superclass

Answer

Simplified debugging

Answer

Reduced memory usage

Answer

Improved program performance

Question 52

Which of the following is NOT a valid example of polymorphism?

Accepted Answer

Overriding a private method in a subclass

Answer

Overloading a method with different parameter types

Answer

Calling a method on an object of a subclass

Question 53

Consider the following code snippet:

`interface Shape { void draw(); } class Circle implements Shape { @Override public void draw() { System.out.println("Drawing a circle"); } } class Rectangle implements Shape { @Override public void draw() { System.out.println("Drawing a rectangle"); } }`

Which of the following statements is true about the code snippet?

Accepted Answer

An array of Shape objects can hold objects of both Circle and Rectangle, demonstrating polymorphism through interfaces.

Answer

The Circle class cannot access the draw() method of the Shape interface.

Answer

The Shape interface cannot have any concrete methods.

Question 54

In which of the following programming languages is polymorphism not supported?

Accepted Answer

C

Answer

Java

Answer

C++

Answer

Python