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 |
___________ 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 2 Explanation:
Process class is a class which implement lower level business abstractions required to manage the business domain class.
Question 3 |
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 3 Explanation:
An ADT does not specify how the data type is implemented.
Question 4 |
Friend functions have access to
Private and protected members | |
Public members only | |
Private members only | |
None |
Question 4 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 5 |
Which of the following supports the concept of multiple inheritance?
C++ | |
Java | |
Both C++ and Java | |
None |
Question 5 Explanation:
C++ supports multiple inheritance whereas java does not.
Question 6 |
In Java, when we implement an interface method, it must be declared as:
Private | |
Protected | |
Public | |
Friend |
Question 7 |
Which one of the following is correct?
Java applets can not be written in any programming language | |
An applet is not a small program | |
An applet can be run on its own | |
Applets are embedded in another applications |
Question 8 |
What is the output of the following JAVA program ?
Class Test {
public static void main(String[] args) {
Test obj = new Test();
obj.start();
}
void start() {
String stra = ”do”;
String strb = method(stra);
System.out.print(“: ”+stra + strb);
}
String method(String stra) {
stra = stra + ”good”;
System.out.print(stra);
return“ good”;
}
}
Class Test {
public static void main(String[] args) {
Test obj = new Test();
obj.start();
}
void start() {
String stra = ”do”;
String strb = method(stra);
System.out.print(“: ”+stra + strb);
}
String method(String stra) {
stra = stra + ”good”;
System.out.print(stra);
return“ good”;
}
}
dogood : dogoodgood | |
dogood : gooddogood | |
dogood : dodogood | |
dogood : dogood |
Question 9 |
Which of the following statements is/are TRUE regarding JAVA ?
(a) Constants that cannot be changed are declared using the ‘static’ keyword.
(b) A class can only inherit one class but can implement multiple interfaces.
Only (a) is TRUE. | |
Only (b) is TRUE. | |
Both (a) and (b) are TRUE. | |
Neither (a) nor (b) are TRUE. |
Question 9 Explanation:
FALSE: Constants that cannot be changed are declared using the ‘static’ keyword.
TRUE: A class can only inherit one class but can implement multiple interfaces.
TRUE: A class can only inherit one class but can implement multiple interfaces.
Question 10 |
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 11 |
Which of the following approach is generally adopted by C++ programming.
Top-down | |
Bottom-up | |
Right-left | |
Left-right |
Question 11 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 12 |
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 12 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 13 |
How many objects can be created in a single class?
1 | |
2 | |
3 | |
as many as required |
Question 13 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 14 |
Which of this process occur automatically by JAVA run time system?
Serialization | |
Garbage collection | |
File Filtering | |
All the given options |
Question 14 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 15 |
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 15 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 16 |
“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 16 Explanation:
“this” is a reference variable that refers to the current object of the class.
Question 17 |
Which of the following is NOT a type of constructor
Copy constructor | |
Friend constructor | |
Default constructor | |
Parameterized constructor |
Question 17 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 18 |
Which one of the following CAN NOT be a friend
function | |
class | |
object | |
operator function |
Question 18 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 19 |
What should be the name of the constructor
same as object
| |
same as member | |
same as class | |
same as function |
Question 19 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 20 |
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 21 |
Java Virtual Machine (JVM) is used to execute architectural neutral byte code. Which of the following is needed by the JVM for execution of Java Code?
Class loader only | |
Class loader and Java Interpreter | |
Class loader, Java Interpreter and API | |
Java Interpreter only |
Question 22 |
Which of the following statements are true regarding C++?
(a) Overloading gives the capacity to an existing operator to operate on other data types.
(b) Inheritance in object oriented programming provides support to reusability.
(c) When object of a derived class is defined, first the constructor of derived class in executed then constructor of a base class is executed.
(d) Overloading is a type of polymorphism. Choose the correct option from those given below:
(a) and (b) only | |
(a), (b) and (c) only | |
(a), (b) and (d) only | |
(b), (c) and (d) only |
Question 22 Explanation:
TRUE: Overloading gives the capacity to an existing operator to operate on other data types.
TRUE: Inheritance in object oriented programming provides support to reusability.
FALSE: When object of a derived class is defined, first the constructor of derived class in executed then constructor of a base class is executed.
2 important points Order of Constructor Call with Inheritance in C++
1. Whether derived class's default constructor is called or parameterised is called, base class's default constructor is always called inside them.
2. To call base class's parameterised constructor inside derived class's parameterised constructor, we must mention it explicitly while declaring derived class's parameterized constructor.
TRUE: Overloading is a type of polymorphism.
TRUE: Inheritance in object oriented programming provides support to reusability.
FALSE: When object of a derived class is defined, first the constructor of derived class in executed then constructor of a base class is executed.
2 important points Order of Constructor Call with Inheritance in C++
1. Whether derived class's default constructor is called or parameterised is called, base class's default constructor is always called inside them.
2. To call base class's parameterised constructor inside derived class's parameterised constructor, we must mention it explicitly while declaring derived class's parameterized constructor.
TRUE: Overloading is a type of polymorphism.
Question 23 |
Let A be the base class in C++ and B be the derived class from A with protected inheritance.
Which of the following statement is false for class B?
Which of the following statement is false for class B?
Member function of class B can access protected data of class A | |
Member function of class access public data of class A | |
Member function of class B cannot access private data of class A | |
Object of derived class B can access public base class data |
Question 23 Explanation:
A→ Base class
B→ Derived class from A with protected inheritance.
The friend functions and the member functions of a friend class can have direct access to both the PRIVATE and PROTECTED data, the member functions of a derived class can directly access only the PROTECTED data.
However, they can access the PRIVATE data through the member functions of the base class TRUE: Member function of class B can access protected data of class A
TRUE: Member function of class access public data of class A
FALSE: Member function of class B cannot access private data of class A
TRUE: Object of derived class B can access public base class data
B→ Derived class from A with protected inheritance.
The friend functions and the member functions of a friend class can have direct access to both the PRIVATE and PROTECTED data, the member functions of a derived class can directly access only the PROTECTED data.
However, they can access the PRIVATE data through the member functions of the base class TRUE: Member function of class B can access protected data of class A
TRUE: Member function of class access public data of class A
FALSE: Member function of class B cannot access private data of class A
TRUE: Object of derived class B can access public base class data
Question 24 |
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 25 |
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 25 Explanation:
In C++ operator, << operator is called as an an insertion operator or put to operator.
Question 26 |
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 26 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 27 |
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 27 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 28 |
Abstract class cannot have
zero instance | |
multiple instance
| |
Both zero instance and multiple instance
| |
None of the given options |
Question 29 |
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 30 |
If x=5, y=2, then x^y equals (where, ^ is a bitwise XOR operator)
00000111 | |
10000010
| |
10100000 | |
11001000 |
Question 30 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 31 |
Run-time polymorphism is achieved by
friend function | |
virtual function
| |
operator overloading | |
function overloading |
Question 31 Explanation:
Run-time polymorphism is achieved by function overriding.
Question 32 |
The operator that cannot be overloaded is
++ | |
:: | |
0 | |
~ |
Question 32 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 33 |
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 34 |
The C++ statement cout <<(0 ==0) will
Outputs as 0 | |
Outputs as 1 | |
Generate error at the time of compilation
| |
Generate run time |
Question 34 Explanation:
The above C++ statement outputs as 1.
Question 35 |
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 35 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 36 |
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 36 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 37 |
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 37 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 38 |
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 39 |
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 39 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 40 |
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 41 |
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 42 |
In Java, for ensuring the persistence property, the class must implements:
Serializable Interface | |
Utilization Interface | |
Threadable Interface | |
Recognizable Interface |
Question 43 |
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 44 |
Which of the following operators cannot be overloaded in C/C++ ?
Bitwise right shift assignment | |
Address of | |
Indirection | |
Structure reference |
Question 44 Explanation:
→ We can’t overload structure reference in C and C++.
→ Bitwise right shift assignment(>>), Address of(&) and Indirection(*) can be overloaded in C and C++.
→ The . (dot) operator and the → (arrow) operator are used to reference individual members of classes, structures, and unions.
→ Bitwise right shift assignment(>>), Address of(&) and Indirection(*) can be overloaded in C and C++.
→ The . (dot) operator and the → (arrow) operator are used to reference individual members of classes, structures, and unions.
Question 45 |
Which of the following cannot be passed to a function in C++ ?
Constant | |
Structure | |
Array | |
Header file |
Question 45 Explanation:
→ Header files contain definitions of Functions and Variables, which is imported or used into any C++ program by using the pre-processor #include statement. Header file have an extension ".h" which contains C++ function declaration and macro definition.
→ Header file is a library file, we can not passed to a function in C++.
→ We can pass constant,Structure and Array
→ Header file is a library file, we can not passed to a function in C++.
→ We can pass constant,Structure and Array
Question 46 |
Which one of the following is correct for overloaded functions in C++ ?
Compiler sets up a separate function for every definition of function. | |
Compiler does not set up a separate function for every definition of function. | |
Overloaded functions cannot handle different types of objects. | |
Overloaded functions cannot have same number of arguments. |
Question 46 Explanation:
→ Function overloading allows you to use the same name for different functions, to perform, either same or different functions in the same class.
→ Compiler sets up a separate function for every definition of function.
→ Two ways to use overloaded function is
1. By changing number of Arguments.
2. By having different types of argument.
→ Compiler sets up a separate function for every definition of function.
→ Two ways to use overloaded function is
1. By changing number of Arguments.
2. By having different types of argument.
Question 47 |
Which of the following storage classes have global visibility in C/C++ ?
Auto | |
Extern | |
Static | |
Register |
Question 47 Explanation:
→ Register and auto variables have limited scope (the block in which they are declared) and limited lifetimes (as for automatic variables). However, in some applications it may be useful to have data which is accessible from within any block and/or which remains in existence for the entire execution of the program. Such variables are called global variables. The scope of external variables is global.
Question 48 |
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 48 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 49 |
In C++, polymorphism requires:
Inheritance only | |
Virtual functions only | |
References only | |
Inheritance, Virtual functions and references |
Question 49 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
Question 50 |
A function template in C++ provides _____ level of generalization.
4 | |
3 | |
2 | |
1 |
Question 50 Explanation:
→ A function template in C++ provides 2 level of generalization.
→ Templates are a feature of the C++ programming language that allows functions and classes to operate with generic types. This allows a function or class to work on many different data types without being rewritten for each one.
→ Templates are a feature of the C++ programming language that allows functions and classes to operate with generic types. This allows a function or class to work on many different data types without being rewritten for each one.
There are 50 questions to complete.