OOP

Question 1

A ____, in the context of Java, are templates that are used to create objects, and to define object data types and methods. Core properties include the data types and methods that may be used by the object

Answer 1

class

Question 2

A ____ can also be defined as a blueprint from which you can create an individual object.

Answer 2

class

Question 3

Any entity that has state and behavior is known as an _____

Answer 3

object

ex. a chair, pen, table, keyboard, bike, etc. It can be physical or logical.

Question 4

An Object can be defined as an instance of a class.

True or False

Answer 4

True

Question 5

An _____ contains an address and takes up some space in memory.

Answer 5

Object

Question 6

OOPs makes development and maintenance easier whereas in a procedure-oriented programming language it is not easy to manage if code grows as project size increases.

True or False

Answer 6

True

Question 7

In OOPs data can be accessed from anywhere, whereas in a procedure-oriented programming language a global data can be hidden.

True or False

Answer 7

FALSE

OOPs provides data hiding whereas in a procedure-oriented programming language a global data can be accessed from anywhere.

Question 8

A _____ is a blueprint from which individual _____ are created.

Answer 8

A class is a blueprint from which individual objects are created.

Question 9

A _________ is called when a instance of the object is created.

Answer 9

constructor

Question 10

When a constructor is created, _____ is allocated for the object.

Answer 10

memory

Question 11

When an object is created, compiler makes sure that constructors for all of its subobjects (its member and inherited objects) are called.

True or False

Answer 11

True

Question 12

A Constructor name does not have to be same same as its class name

True or False

Answer 12

False

Constructor name must be the same as its class name

Question 13

A Constructor must have no explicit return type

True or False

Answer 13

True

Question 14

A Java constructor can be abstract, static, final, and synchronized

Answer 14

False

A Java constructor cannot be abstract, static, final, and synchronized

Question 15

What are the two types of constructors?

Answer 15

• Default Constructor
• Parameterized Constructor

Question 16

The _____ ________ is a no-args constructor that the Java compiler inserts on your behalf; it contains a default call to super(); which is the default behavior.

Answer 16

default constructor

Question 17

The following is an example of type of contructor type?

public Bicycle() {

gear = 1;

cadence = 10;

speed = 0;

}

Answer 17

Default Constructor or No-Argument Constructor

Bicycle yourBike = new Bicycle(); invokes the no-argument constructor to create a new Bicycle object called yourBike.

Question 18

a _____ ________ is added by the compiler when there is no constructor declared in the class.

Answer 18

default constructor

Question 19

What happens to the following constructor when compiled?

class Bike {

}

Answer 19

class Bike {

Bike(){}

}

Question 20

A constructor which has a specific number of parameters is called a __________ _________

Answer 20

Parameterized Constructor

Question 21

This the below class has an example of what type of constructor?

class Student4{

int id;

String name;

Student4(int i,String n){

id = i;

name = n;

}

void display(){System.out.println(id+” “+name);}

public static void main(String args[]){

Student4 s1 = new Student4(111,”Karan”);

Student4 s2 = new Student4(222,”Aryan”);

s1. display();
s2. display();

}

}

Answer 21

parameterized constructor

Question 22

In Java, a constructor is just like a ______ but without return type.

Answer 22

method

Question 23

A class cannot be overloaded like a method.

True or False

Answer 23

False

A class can be overloaded

Question 24

_________ ___________ in Java is a technique of having more than one constructor with different parameter lists.

Answer 24

Constructor overloading

Question 25

When constructors are overloaded each constructor is setup to perform a seperate task. They are differentiated by the compiler by the number of ________ in the list a and their _____.

Answer 25

When constructors are overloaded each constructor is setup to perform a seperate task. They are differentiated by the compiler by the number of parameters in the list a and their types.

Question 26

A method must have a return type

True or False

Answer 26

True

Question 27

The method name may or may not be same as the ____ name.

Answer 27

class

Question 28

The method is invoked ________

Answer 28

explicitly

Question 29

The method can be provided by the compiler

True or False

Answer 29

False

The method is not provided by the compiler in any case.

Question 30

A method is used to _______ the behavior of an object.

Answer 30

expose

Question 31

A constructor is used to ________ the state of an object.

Answer 31

Initialize

Question 32

Can a constructor have a return type

True or False

Answer 32

False

A constructor must not have a return type.

Question 33

The constructor is invoked ______.

Answer 33

implicitly

Question 34

The Java compiler provides a default _________ if you don’t have any constructor in a class.

Answer 34

constructor

Question 35

The constructor name must be same as the class name.

True or False

Answer 35

True