op

Question 1

Which of these is correct way of inheriting class A by class B?

Answer 1

class B extends A {}

Question 2

In java, __________ keyword is used to derive from another class

Answer 2

extends

Question 3

Which class cannot create its instance?

Answer 3

Abstract class

Question 4

Which of these method of ArrayList class is used to obtain present size of an object?

Answer 4

size()

Question 5

How many interfaces can a class implement?

Answer 5

As many as needed

Question 6

What does an interface contain?

Answer 6

Method declaration

Question 7

All the variables of class should be ideally declared as?

Answer 7

private

Question 8

How can the concept of encapsulation be achieved in the program?

Answer 8

By using the Access specifiers

Question 9

______________ is similar to a method but it is called implicitly by the new operator to initialize an object’s instance variables when the object is created

Answer 9

Constructor

Question 10

You can extend the class and create a totally new class that retains all the necessary properties and methods of the parent class from which it has been derived, and then expose new features.
.

Answer 10

Extensibility

Question 11

__________ inheritance is achieved using interface in java

Answer 11

Multiple

Question 12

Which concept of Java is achieved by combining methods and attribute into a class?

Answer 12

Encapsulation

Question 13

Which among the following is correct?

Answer 13

class student{ public: student(){} };

Question 14

Method overriding is combination of inheritance and polymorphism?

Answer 14

true

Question 15

Which of the following is NOT an OOPS concept in Java?

Answer 15

Compilation

Question 16

All classes inherit the cosmic superclass

T

Answer 16

true

Question 17

Getters and setters are ___________ methods which are used if there is a need to provide an indirect access to private fields.

Answer 17

public

Question 18

What is a superclass?

Answer 18

a class that acts as a parent to some other class or classes

Question 19

It is possible to override private or static methods in Java

Answer 19

False

Question 20

Which of the following statements are incorrect?

Answer 20

private members of class can be inherited by a subclass, and become protected members in subclass

Question 21

Polymorphism in Java is of two types, namely ______ and __________

Answer 21

Run time, Compile time

Question 22

Which feature of OOP indicates code reusability?

Answer 22

Inheritance

Question 23

Which of these class relies upon its subclasses for complete implementation of its methods?

Answer 23

abstract class

Question 24

All classes defined without an explicit extends clause automatically extend ___________

Answer 24

Object

Question 25

Data hiding is one of the important features of Object Oriented Programming which allows ___________ the functions of a program to access directly the internal representation (or state of an object) of a class type

Answer 25

preventing

Question 26

Which of the following is FALSE about abstract classes in Java

Answer 26

A class can be made abstract without any abstract method

Question 27

When you need to refactor your projects, OOP gives you the maximum benefit because all objects are small entities and contain its properties and methods as a part of itself.

Answer 27

Reusability

Question 28

Which statement is true?

Answer 28

1.An interface can sub interfaced from other interface 2.Interface support extending 3.Interface can't support extending d. 4.Both 1 and 2

Question 29

In Java programming language, the code is placed inside ___.

Answer 29

All the above

Question 30

Final methods can...

Answer 30

Not be overridden

Question 31

final keyword is only for constants

Answer 31

False

Question 32

__________ inheritance is achieved using interface in java

Answer 32

multiple

Question 33

It is possible to override private or static methods in Java

Answer 33

False

Question 34

All the variables of class should be ideally declared as?

Answer 34

Private

Question 35

Data hiding is one of the important features of Object Oriented Programming which allows ___________ the functions of a program to access directly the internal representation (or state of an object) of a class type

Answer 35

Preventing

Question 36

Which of the following OOP concept binds the code and data together and keeps them secure from the outside world?

Answer 36

Encapsulation

Question 37

Which of these class is superclass of every class in Java?

Answer 37

Object class

Question 38

What is an Encapsulation?

Answer 38

a mechanism of wrapping the data (variables) and code acting on that data (methods) together as a single unit.

Question 39

What is a class?

Answer 39

a prototype that consists of objects in different states and with different behaviors.

Question 40

Which of the statements are correct for Interfaces?

Answer 40

All of the statements

Question 41

Parts of the classes

Answer 41

Constructors, Methods, Fields

Question 42

Which of the statements are incorrect for Interfaces?

Answer 42

We can create objects of an interface

Question 43

Which of these method of ArrayList class is used to obtain present size of an object?

Answer 43

size()

Question 44

What does the modifier protected mean?

Answer 44

accessible in the same package and by subclasses

Question 45

What is inheritance?

Answer 45

a feature of OOPs which allows classes inherit common properties from other classes.

Question 46

Which concept of Java is a way of converting real world objects in terms of class?

Answer 46

Abstraction

Question 47

Which of these keywords can be used to prevent inheritance of a class?

Answer 47

final

Question 48

An abstract class normally contains one abstract methods

Answer 48

False

Question 49

An object is an entity which has bundles of properties and methods can interact with other objects.

Answer 49

Reusability

Question 50

Which of the following is FALSE about abstract classes in Java

Answer 50

A class can inherit from multiple abstract classes.

Question 51

What is the catch statement?

Answer 51

allows you to define a block of code to be tested for errors while it is being executed.

Question 52

What does the Liskov's Substitution principle mean?

Answer 52

to build software systems from interchangeable parts, those parts must adhere to a contract that allows those parts to be substituted one for another.

Question 53

Which of the following statements correct for Lambda Expression?

Answer 53

All of the statements

Question 54

What will be the output in below code? public class Demo{ public static void main(String[] arr){ System.out.println(“Main1”); } public static void main(String arr){ System.out.println(“Main2”);} }

Answer 54

Main1

Question 55

What does the Dependency Inversion principle mean?

Answer 55

you make sure that your class or module has high cohesion, which means that your class does not do more than it should

Question 56

Which of the following statements is correct for OCP?

Answer 56

Objects or entities should be open for extension, but closed for modification

Question 57

For which principle does this statement apply "It should be possible to change an implementation easily without altering high level code"?

Answer 57

DIP

Question 58

Java Generic methods and generic classes enable programmers to specify, with a single method declaration, a set of related methods, or with a single class declaration, a set of related types, respectively

Answer 58

True

Question 59

System generated exceptions are manually thrown by the Java run time system

Answer 59

False

Question 60

Which of the following statements is not correct for ISP?

Answer 60

A client should never depend on anything more that the method which is used

Question 61

What is exception handling?

Answer 61

is a very important concept that is used to manage errors.

Question 62

How many steps we have to connect DB?

Answer 62

6

Question 63

Exception handling enables applications to __________ exceptions

Answer 63

Handle

Question 64

For which principle does this statement apply "A class should have only one reason to change"?

Answer 64

SRP

Question 65

Use throw keyword to manually throw an exception

Answer 65

True​

Question 66

Which of the following statements is not correct for OCP?

Answer 66

Changing a method should not affect on unrelated class

Question 67

Structure of the Lambda expression.

Answer 67

(parameterList) -> {statements}

Question 68

The statement which allows to create a custom error.

Answer 68

throw

Question 69

What does the Interface Segregation principle mean?

Answer 69

A client should never be forced to implement an interface that it doesn't use, or clients shouldn't be forced to depend on methods they do not use.