oops
Question 1 |
A software engineer is required to implement two sets of algorithms for a single set of matrix operations in an object oriented programming language; the two sets of algorithms are to provide precisions of 10-3 and 10-6, respectively. She decides to implement two classes, Low Precision Matrix and High Precision Matrix, providing precisions 10-3 and 10-6 respectively. Which one of the following is the best alternative for the implementation?
- (S1) The two classes should be kept independent.
(S2) Low Precision Matrix should be derived from High Precision Matrix.
(S3) High Precision Matrix should be derived from Low Precision Matrix.
(S4) One class should be derived from the other; the hierarchy is immaterial.
S1 | |
S2 | |
S3 | |
S4 |
Question 1 Explanation:
Note: Out of syllabus.
Question 2 |
The static keyword word is used in public static void main() declaration in java:
To enable the JVM to make call to the main( ), as class has not been instantiated. | |
To enable the JVM to make call to the main( ), as class has not been inherited. | |
To enable the JVM to make call to the main( ), as class has not been loaded. | |
To enable the JVM to make call to the main( ), as class has not been finalized. |
Question 3 |
In Java, for ensuring the persistence property, the class must implements:
Serializable Interface | |
Utilization Interface | |
Threadable Interface | |
Recognizable Interface |
Question 4 |
In the given Program:
class Dialog1
{
public static void main(String args[])
{
Frame f1=new Frame("INDIA");
f1.setSize(300,300);
f1.setVisible(true);
FileDialog d=new FileDialog(f1, "MyDialog");
d.setVisible(true);
String fname=d.getDirectory()+d.getFile();
System.out.println("The Selection is"+fname);
}
}
To make the Frame visible, which of the following statements are true?
class Dialog1
{
public static void main(String args[])
{
Frame f1=new Frame("INDIA");
f1.setSize(300,300);
f1.setVisible(true);
FileDialog d=new FileDialog(f1, "MyDialog");
d.setVisible(true);
String fname=d.getDirectory()+d.getFile();
System.out.println("The Selection is"+fname);
}
}
To make the Frame visible, which of the following statements are true?
f1.setClear(true); | |
f1.setVisible(true); | |
f1.setlook(true); | |
f1.setclean(true); |
Question 5 |
During exception handling, which of the following statements hold true?
Single try can have multiple associated catch with it | |
A Single Catch can have multiple try associated with it | |
Finally block execute only when the class is inherited | |
For a given exception, multiple catch can execute |
Question 6 |
Which of the following are two main types of overloading in Java?
Overloading and linking | |
Overriding and linking | |
Reusability and data-hiding | |
Overloading and Overriding |
Question 6 Explanation:
Overloading occurs when two or more methods in one class have the same method name but different parameters.
Overriding occurs when two methods have the same method name and parameters. One of the methods is in the parent class, and the other is in the child class. Overriding allows a child class to provide the specific implementation of a method that is already present in its parent class.
Overriding occurs when two methods have the same method name and parameters. One of the methods is in the parent class, and the other is in the child class. Overriding allows a child class to provide the specific implementation of a method that is already present in its parent class.
Question 7 |
Given the following statements:
(A) To implement Abstract Data Type, a programming language require a syntactic unit to encapsulate type definition.
(B) To implement ADT, a programming language requires some primitive operations that are built in the language processor.
(C) C++, Ada, Java 5.0, C#2005 provide support for parameterised ADT.
Which one of the following options is correct ?
(A), (B) and (C) are false. | |
(A) and (B) are true; (C) is false.
| |
A) is true; (B) and (C) are false. | |
(A), (B) and (C) are true. |
Question 7 Explanation:
TRUE: To implement Abstract Data Type, a programming language require a syntactic unit to encapsulate type definition.
TRUE: To implement ADT, a programming language requires some primitive operations that are built in the language processor.
TRUE: C++, Ada, Java 5.0, C#2005 provide support for parameterised ADT.
TRUE: To implement ADT, a programming language requires some primitive operations that are built in the language processor.
TRUE: C++, Ada, Java 5.0, C#2005 provide support for parameterised ADT.
Question 8 |
Match the following types of variables with the corresponding programming languages:
(a)-(i), (b)-(iii), (c)-(iv), (d)-(ii) | |
(a)-(iv), (b)-(i), (c)-(iii), (d)-(ii) | |
(a)-(iii), (b)-(i), (c)-(iv), (d)-(ii) | |
(a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)
|
Question 8 Explanation:
Static variables→ Fortran 77
Stack dynamic→ Local variables in Pascal
Explicit heap dynamic→ All objects in JAVA
Implicit heap dynamic→ All variables in APL
Stack dynamic→ Local variables in Pascal
Explicit heap dynamic→ All objects in JAVA
Implicit heap dynamic→ All variables in APL
Question 9 |
Implicit return type of a class constructor is:
not of class type itself | |
class type itself | |
a destructor of class type | |
a destructor not of class type |
Question 9 Explanation:
Implicit return type of a class constructor is class type itself.
Syntax For Constructors:
Access_Modifier No Return_Type Class(...)
Example:
public static main(String [ ]args)
Constructor rules:
1. Constructors are always used with a new.
2. Have the same name as that of Class
3. Does not have a return type
4. Can be Overloaded but not Overridden.
Syntax For Constructors:
Access_Modifier No Return_Type Class(...)
Example:
public static main(String [ ]args)
Constructor rules:
1. Constructors are always used with a new.
2. Have the same name as that of Class
3. Does not have a return type
4. Can be Overloaded but not Overridden.
Question 10 |
It is possible to define a class within a class termed as nested class. There are _____ types of nested classes.
2 | |
3 | |
4 | |
5 |
Question 10 Explanation:
Nested classes are divided into two categories:
1. Static
2. Non static.
Nested classes that are declared static are simply called static nested classes.
Non static nested classes are called inner classes.
1. Static
2. Non static.
Nested classes that are declared static are simply called static nested classes.
Non static nested classes are called inner classes.
Question 11 |
Which of the following statements is correct?
Aggregation is a strong type of association between two classes with full ownership | |
Aggregation is a strong type of association between two classes with partial ownership. | |
Aggregation is a weak type of association between two classes with partial ownership. | |
Aggregation is a weak type of association between two classes with full ownership. |
Question 11 Explanation:
Aggregation is a special form of association. It is a relationship between two classes like association, however its a directional association, which means it is strictly a one way association. It represents a HAS-A relationship.
For example consider two classes Student class and Address class. Every student has an address so the relationship between student and address is a Has-A relationship. But if you consider its vice versa then it would not make any sense as an Address doesn’t need to have a Student necessarily.
For example consider two classes Student class and Address class. Every student has an address so the relationship between student and address is a Has-A relationship. But if you consider its vice versa then it would not make any sense as an Address doesn’t need to have a Student necessarily.
Question 12 |
Which of the following statements is correct?
(1) Every class containing abstract method must not be declared abstract.
(2) Abstract class cannot be directly initiated with ‘new’ operator.
(3) Abstract class cannot be initiated.
(4) Abstract class contains definition of implementation.
(1) Every class containing abstract method must not be declared abstract.
(2) Abstract class cannot be directly initiated with ‘new’ operator.
(3) Abstract class cannot be initiated.
(4) Abstract class contains definition of implementation.
(1) | |
(2) | |
(2) and (3) | |
All are correct. |
Question 12 Explanation:
• Abstract class may consist of at least one abstract method.
• Abstract method means method without body, we can also be called as pure virtual functions.
• If a class is marked with keyword abstract then it is called an abstract class. It can NOT be instantiated by using new operator. But an abstract class can be used as the superclass reference for the subclass object.
• Abstract classes, by design, are not complete or functional. They are meant to serve as a base from which complete classes can be built, by aggregating the common members and methods that they all will need into an abstract base class, and then allowing the inheriting classes to fill out the necessary details. So abstract class can’t be instantiated
• Abstract method means method without body, we can also be called as pure virtual functions.
• If a class is marked with keyword abstract then it is called an abstract class. It can NOT be instantiated by using new operator. But an abstract class can be used as the superclass reference for the subclass object.
• Abstract classes, by design, are not complete or functional. They are meant to serve as a base from which complete classes can be built, by aggregating the common members and methods that they all will need into an abstract base class, and then allowing the inheriting classes to fill out the necessary details. So abstract class can’t be instantiated
Question 13 |
When one object reference variable is assigned to another object reference variable then
a copy of the object is created. | |
a copy of the reference is created. | |
a copy of the reference is not created. | |
it is illegal to assign one object reference variable to another object reference variable. |
Question 13 Explanation:
• A reference variable is an alias, that is, another name for an already existing variable. Once a reference is initialized with a variable, either the variable name or the reference name may be used to refer to the variable.
• A reference variable must be initialized at the time of declaration.
• A reference variable must be initialized at the time of declaration.
Question 14 |
Which of the following is NOT a type of constructor
Copy constructor | |
Friend constructor | |
Default constructor | |
Parameterized constructor |
Question 14 Explanation:
Parameterized constructors: Constructors that can take at least one argument are termed as parameterized constructors. When an object is declared in a parameterized constructor, the initial values have to be passed as arguments to the constructor function.
Default constructors: If the programmer does not supply a constructor for an instantiable class, Java/C++ compiler inserts a default constructor into your code on your behalf. This constructor is known as default constructor.
Copy Constructor: Copy constructors define the actions performed by the compiler when copying class objects. A Copy constructor has one formal parameter that is the type of the class (the parameter may be a reference to an object). It is used to create a copy of an existing object of the same class. Even though both classes are the same, it counts as a conversion constructor.
Default constructors: If the programmer does not supply a constructor for an instantiable class, Java/C++ compiler inserts a default constructor into your code on your behalf. This constructor is known as default constructor.
Copy Constructor: Copy constructors define the actions performed by the compiler when copying class objects. A Copy constructor has one formal parameter that is the type of the class (the parameter may be a reference to an object). It is used to create a copy of an existing object of the same class. Even though both classes are the same, it counts as a conversion constructor.
Question 15 |
Which one of the following CAN NOT be a friend
function | |
class | |
object | |
operator function |
Question 15 Explanation:
The function is not in the scope of the class to which it has been declared as a friend. It cannot be called using the object as it is not in the scope of that class. It can be invoked like a normal function without using the object.
Question 16 |
What should be the name of the constructor
same as object
| |
same as member | |
same as class | |
same as function |
Question 16 Explanation:
Constructor: a constructor (abbreviation: ctor) is a special type of subroutine called to create an object. A constructor resembles an instance method, but it differs from a method in that it has no explicit return type, it is not implicitly inherited and it usually has different rules for scope modifiers. Constructors often have the same name as the declaring class. They have the task of initializing the object's data members
Question 17 |
What is the output of the following program:
#include
class sample
{
private int a,b’
public: void test ( )
{
a = 100;
b = 200;
}
friend int compute (sample e1);
};
int compute (sample e1)
{
return int (e1.a + e1.b) - 5;
}
Main ( )
{
Sample e;
e.test( );
Cout < < compute(e);
}
205 | |
300 | |
295 | |
error |
Question 18 |
Which of the following approach is generally adopted by C++ programming.
Top-down | |
Bottom-up | |
Right-left | |
Left-right |
Question 18 Explanation:
Structure/procedure oriented programming languages like C programming language follows top down approach. Whereas object oriented programming languages like C++ and Java programming language follows bottom up approach.
Question 19 |
Which among the following is the correct way of declaring object of a class
Classname objectname;
| |
Class classname obj objectname; | |
Class classname obj objectname; | |
Classname obj objectname |
Question 19 Explanation:
The correct way of declaring object of a class is
Classname objectname;
For example ,let there be some class of name Area. So we can declare object of Area class like,
Area A1;
For example ,let there be some class of name Area. So we can declare object of Area class like,
Area A1;
Question 20 |
How many objects can be created in a single class?
1 | |
2 | |
3 | |
as many as required |
Question 20 Explanation:
An object is nothing but an instance of a class. A class can have as many instances as required. There is no restriction on the number of objects a class can have.
Question 21 |
Which of this process occur automatically by JAVA run time system?
Serialization | |
Garbage collection | |
File Filtering | |
All the given options |
Question 21 Explanation:
Serialization and deserialization occur automatically by java runtime system, Garbage collection also occur automatically but is done by CPU or the operating system not by the java runtime system
Question 22 |
The ‘new’ operator in JAVA
Returns a pointer to a variable
| |
Creates a variable called new | |
Obtains memory for a new variable | |
Tells how much memory is available |
Question 22 Explanation:
“new” operator in java is used to create a new object. And an object is nothing but an instance of a class. Some memory is allocated to each object for its execution. Hence option(C) is the correct answer.
Question 23 |
“this” keyword in JAVA is used to
Refer to current class object | |
Refer to static method of the class
| |
Refer to parent class object | |
Refer to static variable of the class |
Question 23 Explanation:
“this” is a reference variable that refers to the current object of the class.
Question 24 |
Which of the following features is the best to support JAVA application development distributed across a network of Java Virtual machines?
Remove Method Invocation (RMI) | |
Remote Procedure Calls (RPC) | |
Multicast sockets | |
Remote Method Invocation (RMI) or Remote Procedure Calls (RPC) |
Question 25 |
If a class C is derived from class B which is derived from class A, all though public inheritance, then a class C member function can access
protected and public data in C and B
| |
protected and public data only C | |
private data in A and B
| |
protected data in A and B |
Question 26 |
In C++ operator, << operator is called as
an insertion operator or put to operator | |
an extraction operator or get from operator
| |
an insertion operator or get from operator | |
None of the given options |
Question 26 Explanation:
In C++ operator, << operator is called as an an insertion operator or put to operator.
Question 27 |
Function overloading in C++ is
A group function with the same name
| |
all have the same numbers and type of arguments
| |
functions with same name and same numbers and same type of arguments
| |
None of the given options |
Question 27 Explanation:
Function Overloading is defined as the process of having two or more function with the same name, but different in parameters is known as function overloading in C++. In function overloading, the function is redefined by using either different types of arguments or a different number of arguments.
Question 28 |
How constructor differ from destructor?
Constructors can be overloaded but destructors can’t be overloaded | |
Constructors can take arguments but destructor can’t | |
Constructors can be overloaded but destructors can’t be overloaded and Constructors can take arguments but destructor can’t
| |
None of the given options
|
Question 28 Explanation:
Constructors can be overloaded but destructors can’t be overloaded.
Destructors cant be overloaded because your code wouldn't have a clue about which destructor it needs to call when you destroy an object.
Destructors cant be overloaded because your code wouldn't have a clue about which destructor it needs to call when you destroy an object.
Question 29 |
Abstract class cannot have
zero instance | |
multiple instance
| |
Both zero instance and multiple instance
| |
None of the given options |
Question 30 |
Usually a pure virtual function
has complete function body | |
will never be called | |
will be called only to delete an object
| |
is defined only in derived class
|
Question 31 |
If x=5, y=2, then x^y equals (where, ^ is a bitwise XOR operator)
00000111 | |
10000010
| |
10100000 | |
11001000 |
Question 31 Explanation:
In XOR,
1 XOR 1 = 0
1 XOR 0 =1
0 XOR 0 = 0
0 XOR 1 = 1
So 5 in binary form is 00000101 and 2 in binary form is 00000010.
Hence 00000101 XOR 00000010 = 00000111.
1 XOR 1 = 0
1 XOR 0 =1
0 XOR 0 = 0
0 XOR 1 = 1
So 5 in binary form is 00000101 and 2 in binary form is 00000010.
Hence 00000101 XOR 00000010 = 00000111.
Question 32 |
Run-time polymorphism is achieved by
friend function | |
virtual function
| |
operator overloading | |
function overloading |
Question 32 Explanation:
Run-time polymorphism is achieved by function overriding.
Question 33 |
The operator that cannot be overloaded is
++ | |
:: | |
0 | |
~ |
Question 33 Explanation:
There are 4 operators that cannot be overloaded in C++. They are :: (scope resolution), . (member selection), . * (member selection through pointer to function) and ?: (ternary operator).
Question 34 |
The keyword friend does not appear in
the class allowing access to another class | |
the class desiring access to another class | |
the private section of a class
| |
the public section of a class |
Question 35 |
Which of the following supports the concept of multiple inheritance?
C++ | |
Java | |
Both C++ and Java | |
None |
Question 35 Explanation:
C++ supports multiple inheritance whereas java does not.
Question 36 |
Friend functions have access to
Private and protected members | |
Public members only | |
Private members only | |
None |
Question 36 Explanation:
A friend function of a class is defined outside that class' scope but it has the right to access all private and protected members of the class.
Question 37 |
Which of the following is not specified in Abstract data type?
Type | |
Set of operations on that type | |
How the type is implemented | |
(A) and (B) |
Question 37 Explanation:
An ADT does not specify how the data type is implemented.
Question 38 |
___________ is a class which implement lower level business abstractions required to manage the business domain class :
User interface class | |
System class | |
Business domain class | |
Process class |
Question 38 Explanation:
Process class is a class which implement lower level business abstractions required to manage the business domain class.
Question 39 |
The C++ statement cout <<(0 ==0) will
Outputs as 0 | |
Outputs as 1 | |
Generate error at the time of compilation
| |
Generate run time |
Question 39 Explanation:
The above C++ statement outputs as 1.
Question 40 |
Which of the following statements is true about C++ language?
C++ supports multiple inheritance | |
C++ does not support operator overloading. | |
C++ supports dynamic polymorphism
| |
C++ supports interface definitions. | |
Both A and D |
Question 40 Explanation:
C++ supports multiple inheritance.
C++ supports operator overloading.
C++ supports static polymorphism.
C++ supports interface definitions.
C++ supports operator overloading.
C++ supports static polymorphism.
C++ supports interface definitions.
Question 41 |
Which of the following statement is not True?
A data member of a class can be declared as static and is normally used to maintain values
common to the entire class. | |
A friend function can be invoked like a normal function without the help of any object. | |
The scope resolution operator (::) can overloaded like normal operators | |
Multiple may lead to duplication of inherited members from a "Grandparent"
base class. This may be avoided by making the common base class a virtual base class.
|
Question 42 |
Which of the following C++ statements correctly declares an abstract class?
Class A {virtual void show() = 0; };
| |
Class A {void show() = 0;};
| |
Class A {void show() { } ; };
| |
Class A {show() = 0; }; |
Question 43 |
Which of the following are TRUE about constructions in C++ ?
(A)A constructor can be overloaded.
(B)A constructor does not have a return type.
(C)A constructor must be declared as a friend function.
(D)A constructor is called when an object is destroyed.
Choose the correct answer from the options green
(A)A constructor can be overloaded.
(B)A constructor does not have a return type.
(C)A constructor must be declared as a friend function.
(D)A constructor is called when an object is destroyed.
Choose the correct answer from the options green
(B), (C), (D) only
| |
(B), (C) only
| |
(A),(B), (C) only
| |
(A),(B) Only |
Question 44 |
What is the output of the code given below :
#include
Using namespace std;
class Base {
public:
Base(){
cout<<”Base const”;
}
Virtual ~Base()
{
cout<<”Base dest”;
}
};
class derived : public Base{
public:
Derived (){
cout<<”Derived Const”;
}
~ Derived(){
cout<< “Derived dest”;
}
};
int main ()
{
Base *b = new Derived ();
delete b;
return 0;
}
#include
Using namespace std;
class Base {
public:
Base(){
cout<<”Base const”;
}
Virtual ~Base()
{
cout<<”Base dest”;
}
};
class derived : public Base{
public:
Derived (){
cout<<”Derived Const”;
}
~ Derived(){
cout<< “Derived dest”;
}
};
int main ()
{
Base *b = new Derived ();
delete b;
return 0;
}
Base Const Derived Const Derived dest Base dest
| |
Base Const Derived Const Base dest Derived dest
| |
Derived Const Base Const Base dest Derived dest | |
Base Const Derived Const Base dest
|
Question 45 |
A three dimensional array in C++ is declared as int A[a][b][c].consider that array elements are stored in row major order and indexing begin from 0.Here the address of an item at the location A[r][s][t] computed in terms of word length w of an integer is
&A[0][0][0]+w(b*c*s+c*r+t)
| |
&A[0][0][0]+w(b*c*r*+c*s+t)
| |
&A[0][0][0]+w(a*b*r*+c*s+t)
| |
&A[0][0][0]+w(a*b*s+c*r+t) |
Question 45 Explanation:
To compute the address of an item at the location A[r][s][t] in a three-dimensional array stored in row-major order as follows
&A[0][0][0] + w * (b * c * r + c * s + t)
Question 46 |
If a constructor 'Date' is declared explicitly and has to be defined outside the class, which of the following is correct?
Date::Date(int dd) {/*...*/} | |
explicit Date::Date(int dd) {/*...*/} | |
Such a constructor cannot be defined | |
Constructor always has to be defined inside the class |
Question 46 Explanation:
Defining a Constructor Outside of the Class :Although the constructor can be defined outside of the class, it must be declared inside class. Use the scope resolution operator while defining a constructor outside of the class.
class class_name {
public:
class_name();
};
// Defining a Constructor Outside of the Class by using :: operator
class_name::class_name()
{
}
class class_name {
public:
class_name();
};
// Defining a Constructor Outside of the Class by using :: operator
class_name::class_name()
{
}
Question 47 |
Match List I with List II:
List I List II
(A) Localization (I) Encapsulation
(B) Packaging or binding of a collection of items (II) Abstraction
(C) Mechanism that enables designer to focus on essential details of a program component (III) Characteristics of software that indicate the manner in which information is concentrated in a program.
(D) Information hiding (IV) Suppressing the operational details of a program component
Choose the correct answer from the options given below:
List I List II
(A) Localization (I) Encapsulation
(B) Packaging or binding of a collection of items (II) Abstraction
(C) Mechanism that enables designer to focus on essential details of a program component (III) Characteristics of software that indicate the manner in which information is concentrated in a program.
(D) Information hiding (IV) Suppressing the operational details of a program component
Choose the correct answer from the options given below:
(A)-(I), (B)-(II), (C)-(III), (D)-(IV) | |
(A)-(II), (B)-(I), (C)-(III), (D)-(IV) | |
(A)-(III), (B)-(I), (C)-(II), (D)-(IV) | |
(A)-(III), (B)-(I), (C)-(IV), (D)-(II) |
Question 48 |
A subclass having more than one super class is called __________ .
Category | |
Classification | |
Combination | |
Partial participation |
Question 48 Explanation:
A subclass having more than one super class is called category.
Question 49 |
If a function is friend of a class, which one of the following is wrong?
A function can only be declared a friend by a class itself. | |
Friend functions are not members of a class, they are associated with it. | |
Friend functions are members of a class. | |
It can have access to all members of the class, even private ones. |
Question 49 Explanation:
→ A friend function of a class is defined outside that class' scope but it has the right to access all private and protected members of the class. Even though the prototypes for friend functions
appear in the class definition, friends are not member functions.
TRUE: function can only be declared a friend by a class itself.
TRUE: Friend functions are not members of a class, they are associated with it.
FALSE:Friend functions are members of a class.
TRUE: It can have access to all members of the class, even private ones.
TRUE: function can only be declared a friend by a class itself.
TRUE: Friend functions are not members of a class, they are associated with it.
FALSE:Friend functions are members of a class.
TRUE: It can have access to all members of the class, even private ones.
Question 50 |
In C++, polymorphism requires:
Inheritance only | |
Virtual functions only | |
References only | |
Inheritance, Virtual functions and references |
Question 50 Explanation:
→ Polymorphism means "many forms", and it occurs when we have many classes that are related to each other by inheritance.
→ In C++, polymorphism requires inheritance, virtual functions and references
→ In C++, polymorphism requires inheritance, virtual functions and references
There are 50 questions to complete.