FINALTERM EXAMINATION
Fall 2009
CS304- Object Oriented Programming (Session - 1)
Time: 120 min
Marks: 75
Question No: 1 ( Marks: 1 ) - Please choose one
Which one of the following terms must relate to polymorphism?
Static allocation
Static typing
Dynamic binding
Dynamic allocation
Question No: 2 ( Marks: 1 ) - Please choose one
Multiple inheritance can be of type
Question No: 3 ( Marks: 1 ) - Please choose one
When a subclass specifies an alternative definition for an attribute or method of its
superclass, it is _______ the definition in the superclass.
overload
overriding
copy riding
none of given
Question No: 4 ( Marks: 1 ) - Please choose one
Like template functions, a class template may not handle all the types successfully.
True
False
Question No: 5 ( Marks: 1 ) - Please choose one
It is sometimes useful to specify a class from which no objects will ever be created.
True
False
Question No: 6 ( Marks: 1 ) - Please choose one
Assume a class Derv that is privately derived from class Base. An object of class Derv
located in main() can access
public members of Derv.
protected members of Derv.
private members of Derv.
protected members of Base.
Question No: 7 ( Marks: 1 ) - Please choose one
A pointer to a base class can point to objects of a derived class.
True
False
Question No: 8 ( Marks: 1 ) - Please choose one
A copy constructor is invoked when
a function do not returns by value.
an argument is passed by value.
a function returns by reference.
an argument is passed by reference.
Question No: 9 ( Marks: 1 ) - Please choose one
A function call is resolved at run-time in___________
non-virtual member function.
virtual member function.
Both non-virtual member and virtual member function.
None of given
Question No: 10 ( Marks: 1 ) - Please choose one
When the base class and the derived class have a member function with the same name,
you must be more specific which function you want to call (using ___________).
scope resolution operator
dot operator
null operator
Operator overloading
Question No: 11 ( Marks: 1 ) - Please choose one
Each try block can have ______ no. of catch blocks.
1
2
3
As many as necessary.
Question No: 12 ( Marks: 1 ) - Please choose one
Two important STL associative containers are _______ and _______.
set,map
sequence,mapping
setmet,multipule
sit,mat
Question No: 13 ( Marks: 1 ) - Please choose one
The mechanism of selecting function at run time according to the nature of calling object
is called,
late binding
static binding
virtual binding
None of the given options
Question No: 14 ( Marks: 1 ) - Please choose one
An abstract class is useful when,
We do not derive any class from it.
There are multiple paths from one derived class to another.
We do not want to instantiate its object.
You want to defer the declaration of the class.
Question No: 15 ( Marks: 1 ) - Please choose one
Which of the following is incorrect line regarding function template?
template<class T>
template <typename U>
Class<template T>
template < class T, class U>
Question No: 16 ( Marks: 1 ) - Please choose one
Which of the following is/are advantage[s] of generic programming?
Reusability
Writability
Maintainability
All of given
Question No: 17 ( Marks: 1 ) - Please choose one
By default the vector data items are initialized to ____
0
0.0
1
null
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Question No: 18 ( Marks: 1 ) - Please choose one
Which one of the following functions returns the total number of elements in a vector.
length();
size();
ele();
veclen();
Question No: 19 ( Marks: 1 ) - Please choose one
Suppose you create an uninitialized vector as follows:
vector<int> evec;
After adding the statment,
evec.push_back(21);
what will happen?
The following statement will add an element to the start (the back) of evec and
will initialize it with the value 21.
The following statement will add an element to the center of evec and will
reinitialize it with the value 21.
The following statement will delete an element to the end (the back) of evec and
will reinitialize it with the value 21.
The following statement will add an element to the end (the back) of evec and
initialize it with the value 21.
Question No: 20 ( Marks: 1 ) - Please choose one
An STL container can not be used to,
hold objects of class employee.
store elements in a way that makes them quickly accessible.
compile c++ programs.
organize the way objects are stored in memory
Question No: 21 ( Marks: 1 ) - Please choose one
Algorithms can only be implemented using STL containers.
True
False
Question No: 22 ( Marks: 1 ) - Please choose one
The main function of scope resolution operator (::) is, eagle_eye
To define an object
To define a data member
To link the definition of an identifier to its declaration
To make a class private
Question No: 23 ( Marks: 1 ) - Please choose one
When is a constructor called?
Each time the constructor identifier is used in a program statement
During the instantiation of a new object
During the construction of a new class
At the beginning of any program execution
Question No: 24 ( Marks: 1 ) - Please choose one
Consider the code below,
class Fred {
public:
Fred();
...
};
int main()
{
Fred a[10];
Fred* p = new Fred[10];
...
}
Select the best option,
Fred a[10]; calls the default constructor 09 times
Fred* p = new Fred[10]; calls the default constructor 10 times
Produce an error
Fred a[10]; calls the default constructor 11 times
Fred* p = new Fred[10]; calls the default constructor 11 times
Fred a[10]; calls the default constructor 10 times
Fred* p = new Fred[10]; calls the default constructor 10 times
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Question No: 25 ( Marks: 1 ) - Please choose one
Associativity can be changed in operator overloading.
True
False
Question No: 26 ( Marks: 1 ) - Please choose one
A normal C++ operator that acts in special ways on newly defined data types is said to
be
glorified.
encapsulated.
classified.
overloaded.
Question No: 27 ( Marks: 1 ) - Please choose one
Which operator can not be overloaded?
The relation operator ( >= )
Assignment operator ( = )
Script operator ( [] )
Conditional operator (? : )
Question No: 28 ( Marks: 1 ) - Please choose one
Suppose obj1 and obj2 are two objects of a user defined class A. An + operator is
overloaded to add obj1 and obj2 using the function call obj1+obj2.
Identify the correct function prototype against the given call?
A operator + ( A &obj);
int + operator();
int operator (plus) ();
A operator(A &obj3);
Question No: 29 ( Marks: 1 ) - Please choose one
Default constructor is such constructor which either has no ---------or if it has some
parameters these have -------- values
Parameter, temporary
Null, Parameter
Parameter, default
non of the given
Question No: 30 ( Marks: 1 ) - Please choose one
Public methods of base class can --------- be accessed in its derived class
directly
inderectly
simultaniously
non of the given
Question No: 31 ( Marks: 1 )
Is Deque a Birectional Container?
Yes, deque behaves like queue (line) such that we can add elements on both sides of it.
Question No: 32 ( Marks: 1 )
What is meant by Generic Programming?
Generic programming refers to programs containing generic abstractions general code
that is same in logic for all data types like printArray function), then we instantiate that
generic program abstraction (function, class) for a particular data type, such abstractions
can work with many different types of data.
Question No: 33 ( Marks: 2 )
Sort the following data in the order in which compiler searches a function?
Complete Specialization, Generic Template, Partial Specialization, Ordinary Function.
Specializations of this function template, instantiations with specific types, can be called
just like an ordinary function:
cout << max(3, 7); // outputs 7
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The compiler examines the arguments used to call max and determines that this is a call
to max(int, int). It then instantiates a version of the function where the parameterizing
type T is int, making the equivalent of the following function:
int max(int x, int y)
{
return x < y ? y : x;
}
the C++ Standard Template Library contains the function template max(x, y) which
creates functions that return either x or y, whichever is larger. max() could be defined like
this:
template <typename T>
T max(T x, T y)
{
return x < y ? y : x;
}
Question No: 34 ( Marks: 2 )
State any conflict that may rise due to multiple inheritance?
The conflict may arise is the diamond problem, which our author likes to call the
“diamond of doom”. This occurs when a class multiply inherits from two classes which
each inherit from a single base class. This leads to a diamond shaped inheritance pattern.
For example, consider the following set of classes:
classPoweredDevice
{
};
classScanner: publicPoweredDevice
{
};
classPrinter: publicPoweredDevice
{
};
classCopier: publicScanner, publicPrinter
{
};
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Scanners and printers are both powered devices, so they derived from PoweredDevice.
However, a copy machine incorporates the functionality of both Scanners and Printers.
Ambiguity also cause problem.
Question No: 35 ( Marks: 3 )
Describe three properties necessary for a container to implement Generic Algorithms.
If you declare a container as holding pointers, you are responsible for managing the
memory for the objects pointed to. The container classes will not automatically free
memory for these objects when an item is erased from the container.
Container classes are expected to implement methods to do the following:
• create a new empty container (constructor),
• report the number of objects it stores (size),
• delete all the objects in the container (clear),
• insert new objects into the container,
• remove objects from it,
• provide access to the stored objects.
Question No: 36 ( Marks: 3 )
Write three important features of virtual functions.
With virtual functions, derived classes can provide new implementations of functions
from their base classes. When someone calls a virtual function of an object of the derived
class, this new implementation is called, even if the caller uses a pointer to the base class,
and doesn't even know about the particular derived class.
The virtual function is an option, and the language defaults to non virtual, which is the
fastest configuration.
The derived class can completely "override" the implementation or "augment" it (by
explicitly calling the base class implementation in addition to the new things it does). eagle_eye
Question No: 37 ( Marks: 3 )
Consider the code below,
#include <iostream>
#include <stdlib.h>
using namespace std;
class Shape{
public:
void Draw(){cout<<"shape"<<endl;}
};
class Line : public Shape{
public:
void Draw(){cout<<"Line"<<endl;}
};
class Circle : public Shape{
public:
void Draw(){cout<<"Circle"<<endl;}
};
int main(int argc, char *argv[])
{
Shape * ptr1 = new Shape();
Shape * ptr2 = new Line();
Shape * ptr3 = new Circle();
ptr1->Draw();
ptr2->Draw();
ptr3->Draw();
system("PAUSE");
return 0;
}
This code shows output,
Shape
Shape
Shape
Give the reason for this output
Suppose we want to show the output,
Shape
Line
Circle eagle_eye
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How we can change the code to do that?
class shape { public:
void draw();
};
class circle : public shape { };
int main(int argc, char **argv){
circle my_circle;
my_circle.draw();
}
While this has all the usual advantages, e.g., code reuse, the real power of polymorphism
comes into play when draw is declared to be virtual or pure virtual, as follows:
class shape{ public:
virtual void draw()=0;
};
class circle : public shape { public:
void draw();
}
Here, circle has declared its own draw function, which can define behavior appropriate
for a circle. Similarly, we could define other classes derived from shape, which provide
their own versions of draw. Now, because all the classes implement the shape interface,
we can create collections of objects that can provide different behavior invoked in a
consistent manner (calling the draw member function). An example of this is shown here.
shape *shape_list[3]; // the array that will
// pointer to our shape objects
shape[0] = new shape; // three types of shapes
shape[1] = new line; // we have defined
shape[2] = new circle;
for(int i = 0; i < 3; i++){
shape_list[i].draw();
}
When we invoke the draw function for each object on the list, we do not need to know
anything about each object; C++ handles the details of invoking the correct version of
draw. This is a very powerful technique, allowing us to provide extensibility in our
designs. Now we can add new classes derived from shape to provide whatever behavior
we desire. The key here is that we have separated the interface (the prototype for shape)
from the implementation.
Question No: 38 ( Marks: 5 )
There are some errors in the code given below, you have to
1. Indicate the line no. with error/s
2. Give the reason for error/s
3. Correct the error/s.
1. #include <iostream> this will be #include <iostream.h>
2. #include <stdlib.h>
3. using namespace std;
4. template <typename T>
5. class MyClass{
6. public:
7. MyClass(){
8. cout<<"This is class1"<<endl;
9. }
10. };
11. template <typename T>
12. class MyClass<int*>{
13. public:
14. MyClass(){
15. cout<<"This is class2"<<endl;
16. }
17. };
18. int main(int argc, char *argv[])
19. {
20. MyClass<int> c1;
21. MyClass<int*> c2;
22. system("PAUSE");
23. return 0;
24. }
Question No: 39 ( Marks: 5 )
Given are two classes A and B. class B is inherited from class A. Write a code
snippet(for main function) that polymorphically call the method of class B. Also what
changes do you suggest in the given code segment that are required to call the class B
method polymorphically.
class A
{
public:
void method() { cout<<"A's method \n"; }
};
class B : public A
{
public:
void method() { cout<<"B's method\n"; }
};
Ans:
public class Test
{
public class A {}
public class B extends A {}
private void test(A a)
{
System.out.println("test(A)");
}
private void test(B b)
{
System.out.println("test(B)");
}
public static void main(String[] args)
{
Test t = new Test();
A a = t.new A();
A b = t.new B();
t.test(a);
t.test(b);
}
}
Question No: 40 ( Marks: 10 )
Create built-in STL (Standard Template Library) vector class object for strings
and add in it some words by taking input from user, then apply the sort()
algorithm to array of words stored in this vector class object.
Hint:Use push_back() to add the words in vector class object, and the [] operator
and size() to display these sorted words.
The STL is the containers, iterators and algorithms component of the proposed C++
Standard Library [ANSI95]. It represents a novel application of principles which have
their roots in styles of programming other than Object-orientation.
void listWords(istream& in, ostream& out)
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{
string s;
while (!in.eof() && in >> s) {
add s to some container
}
sort the strings in the container
remove the duplicates
for (each string t in container) {
out << t;
}
}
For now, assume that a word is defined as a whitespace-separated string as delivered by
the stream extraction operator. Later on we will consider ways of refining this definition.
Given the way this problem is expressed, we can implement this program directly, if
naïvely. The STL container class vector will suffice to hold the words: applying the
algorithms sort and unique provides the required result.
void listWords(istream& in, ostream& out)
{
string s;
vector<string> v;
while (!in.eof() && in >> s)
v.push_back(s); // (1)
sort(v.begin(), v.end());
vector<string>::iterator e
= unique(v.begin(), v.end()); // (2)
for (vector<string>::iterator b = v.begin();
b != e;
b++) {
out << *b << endl;
}
}
At (1) the vector member function push_back() is used to add to the end of the vector.
This can also be done using the insert member, which takes as a parameter an iterator
identifying the position in the vector at which to place the added element:
v.insert(v.end(), s);
This allows us to add at any position in the vector. Be aware, though, that adding
anywhere other than the end implies the overhead of physically shifting all elements from
the insertion point to the end to make room for the new value. For this reason, and given
the choices made in this example, attempts to optimise this code by maintaining the
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vector in sorted order are unwise. Replace vector with list and this becomes possible -
although in both cases a search over the container will be necessary to determine the
correct position of insertion.
The unique algorithm has the surprising property of not changing the length of the
container to which it is applied (it can hardly do this, as it has access not to the
underlying container, but only to the pair of iterators it is passed). Instead, it guarantees
that duplicates are removed by moving unique entries towards the beginning of the
container, returning an iterator indicating the new end of the container. This can be used
directly (as here, at (2)), conversely it can be passed to the erase member with the old end
iterator, to truncate the container.
Question No: 41 ( Marks: 10 )
Q. Write a detailed note on Exceptions in Destructors with the help of a coding
example.
Exceptions in Destructors:
An object is presumably created to do something. Some of the changes made by an object
should persist after an object dies (is destructed) and some changes should not. Take an
object implementing a SQL query. If a database field is updated via the SQL object then
that change should persist after the SQL objects dies. To do its work the SQL object
probably created a database connection and allocated a bunch of memory. When the SQL
object dies we want to close the database connection and deallocate the memory,
otherwise if a lot of SQL objects are created we will run out of database connections
and/or memory.
The logic might look like:
Sql::~Sql()
{
delete connection;
delete buffer;
}
Let's say an exception is thrown while deleting the database connection. Will the buffer
be deleted? No. Exceptions are basically non-local gotos with stack cleanup. The code for
deleting the buffer will never be executed creating a gaping resource leak.
Special care must be taken to catch exceptions which may occur during object
destruction. Special care must also be taken to fully destruct an object when it throws an
exception.
Example code for exception ……
#include<iostream.h>
#include<conio.c>
class Exception {
private:
eagle_eye
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char message[30] ;
public:
Exception() {strcpy(message,"There is not enough stock");}
char * get_message() { return message; }
};
class Item {
private:
int stock ;
int required_quantity;
public:
Item(int stk, int qty)
{
stock = stk;
required_quantity = qty;
}
int get_stock()
{
return stock;
}
int get_required_quantity()
{
return required_quantity;
}
void order()
{
if (get_stock()< get_required_quantity())
throw Exception();
else
cout<<"The required quantity of item is available in the stock";
}
~Item(){}
};
void main()
{
Item obj(10, 20);
try eagle_eye
{
obj.order();
}
catch(Exception & exp2)
{
getch();
cout << "Exception: " << exp2.get_message() << endl;
}
getch();
FINALTERM EXAMINATION
Fall 2009
CS304- Object Oriented Programming (Session - 4)
Ref No: 1130772
Time: 120 min
Marks: 75
Question No: 1 ( Marks: 1 ) - Please choose one
A template provides a convenient way to make a family of
variables and data members
functions and classes
classes and exceptions
programs and algorithms
Question No: 2 ( Marks: 1 ) - Please choose one
Which one of the following terms must relate to polymorphism?
Static allocation
Static typing
Dynamic binding
Dynamic allocation
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Question No: 3 ( Marks: 1 ) - Please choose one
What is true about function templates?
The compiler generates only one copy of the function template
The compiler generates a copy of function respective to each type of data
The compiler can only generate copy for the int type data
None of the given.
Question No: 4 ( Marks: 1 ) - Please choose one
Which of the following is the best approach if it is required to have more than one
functions having exactly same functionality and implemented on different data types?
Templates
Overloading
Data hiding
Encapsulation
Question No: 5 ( Marks: 1 ) - Please choose one
template <>
class Vector<char*> { }
This is an example of partial specialization.
True
False
Question No: 6 ( Marks: 1 ) - Please choose one
Classes like TwoDimensionalShape and ThreeDimensionalShape would normally be
concrete, while classes like Sphere and Cube would normally be abstract.
True
False
Question No: 7 ( Marks: 1 ) - Please choose one eagle_eye
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A non-virtual member function is defined in a base class and overridden in a derived
class; if that function is called through a base-class pointer to a derived class object, the
derived-class version is used.
True
False
Question No: 8 ( Marks: 1 ) - Please choose one
Assume a class Derv that is privately derived from class Base. An object of class Derv
located in main() can access
public members of Derv.
protected members of Derv.
private members of Derv.
protected members of Base.
Question No: 9 ( Marks: 1 ) - Please choose one
In order to define a class template, the first line of definition must be:
template <typename T>
typename <template T>
Template Class <ClassName>
Class <Template T>
Question No: 10 ( Marks: 1 ) - Please choose one
If there is a pointer p to objects of a base class, and it contains the address of an object of
a derived class, and both classes contain a nonvirtual member function, ding(), then the
statement p->ding(); will cause the version of ding() in the _____ class to be executed.
Base
Derived eagle_eye
Abstract
virtual
Question No: 11 ( Marks: 1 ) - Please choose one
When the base class and the derived class have a member function with the same name,
you must be more specific which function you want to call (using ___________).
scope resolution operator
dot operator
null operator
Operator overloading
Question No: 12 ( Marks: 1 ) - Please choose one
Non Template Friend functions of a class are friends of ________instance/s of that class.
All
One specific
All instances of one date type
None of the given options
Question No: 13 ( Marks: 1 ) - Please choose one
The find() algorithm
finds matching sequences of elements in two containers.
finds a container that matches a specified container.
takes iterators as its first two arguments.
takes container elements as its first two arguments.
Question No: 14 ( Marks: 1 ) - Please choose one
If you define a vector v with the default constructor, and define another vector w with a
one-argument constructor to a size of 11, and insert 3 elements into each of these vectors
with push_back(), then the size() member function will return ______ for v and _____ for
w.
11 for v and 3 for w. eagle_eye
0 for v and 0 for w.
0 for v and 3 for w.
3 for v and 11 for w.
Question No: 15 ( Marks: 1 ) - Please choose one
Which of the following may not be an integral part of an object?
State
Behavior
Protected data members
All of given
Question No: 16 ( Marks: 1 ) - Please choose one
Which is not the Advantage of inheritance?
providing class growth through natural selection.
facilitating class libraries.
avoiding the rewriting of code.
providing a useful conceptual framework.
Question No: 17 ( Marks: 1 ) - Please choose one
class DocElement
{
public:
virtual void Print() { cout << "Generic element"; }
};
class Heading : public DocElement
{
public:
void Print() { cout << "Heading element"; }
};
class Paragraph : public DocElement
{
public:
void Print() { cout << "Paragraph element"; }
}; eagle_eye
void main()
{
DocElement * p = new Paragraph();
p->Print();
}
When you run this program, it will print out a single line to the console output.
What will be in that line?
Select one correct answer from the following list:
Generic element
Heading element
Paragraph element
Nothing will be printed.
Question No: 18 ( Marks: 1 ) - Please choose one
When a virtual function is called by referencing a specific object by name and using the
dot member selection operator (e.g., squareObject.draw()), the reference is resolved at
compile time.
True
False
Question No: 19 ( Marks: 1 ) - Please choose one
In case of multiple inheritance a derived class inherits,
Only the public member functions of its base classes
Only the public data members of its base classes
Both public data members and member functions of all its base classes
Data members and member functions of any two base classes
Question No: 20 ( Marks: 1 ) - Please choose one
When we write a class template the first line must be: eagle_eye
template < class class_name>
template < class data_type>
template < class T >
Here T can be replaced with any name but it is preferable.
class class-name()
class template<class_name>
Question No: 21 ( Marks: 1 ) - Please choose one
Which of the following is incorrect line regarding function template?
template<class T>
template <typename U>
Class<template T>
template < class T, class U>
Question No: 22 ( Marks: 1 ) - Please choose one
An STL container can not be used to,
hold objects of class employee.
store elements in a way that makes them quickly accessible.
compile c++ programs.
organize the way objects are stored in memory
Question No: 23 ( Marks: 1 ) - Please choose one
Algorithms can only be implemented using STL containers.
True
False
Question No: 24 ( Marks: 1 ) - Please choose one
Consider a class named Vehicle, which of the following can be the instance of class
Vehicle? eagle_eye
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1. Car
2. Computer
3. Desk
4. Ahmed
5. Bicycle
6. Truck
1, 4, 5
2, 5, 6
1, 2, 3, 6
1, 5, 6
Question No: 25 ( Marks: 1 ) - Please choose one
Consider the code below,
class Fred {
public:
Fred();
...
};
int main()
{
Fred a[10];
Fred* p = new Fred[10];
...
}
Select the best option,
Fred a[10]; calls the default constructor 09 times
Fred* p = new Fred[10]; calls the default constructor 10 times
Produce an error
Fred a[10]; calls the default constructor 11 times
Fred* p = new Fred[10]; calls the default constructor 11 times
Fred a[10]; calls the default constructor 10 times
Fred* p = new Fred[10]; calls the default constructor 10 times
Question No: 26 ( Marks: 1 ) - Please choose one
When a variable is define as static in a class then all object of this class,
eagle_eye
Have different copies of this variable
Have same copy of this variable
Can not access this variable
None of given
Question No: 27 ( Marks: 1 ) - Please choose one
The life of sub object is dependant on the life of master class in _____________.
Separation
Composition
Aggregation
None of the given
Question No: 28 ( Marks: 1 ) - Please choose one
___________, which means if A declares B as its friend it does NOT mean that A can
access private data of B. It only means that B can access all data of A.
Friendship is one way only
Friendship is two way only
NO Friendship between classes
Any kind of friendship
Question No: 29 ( Marks: 1 ) - Please choose one
Which of the following operators always takes no argument if overloaded?
/
-
+
++
eagle_eye
Question No: 30 ( Marks: 1 ) - Please choose one
In Private -------------- only member functions and friend classes or functions of a
derived class can convert pointer or reference of derived object to that of parent object
specialization
inheritance
abstraction
composition
Question No: 31 ( Marks: 1 )
Write the syntax of declaring a pure virtual function in a class?
Ans:
Pure Virtual Function is a Virtual function with no body.
Declaration of Pure Virtual Function:
Since pure virtual function has no body, the programmer must add the notation =0 for
declaration of the pure virtual function in the base class.
General Syntax of Pure Virtual Function takes the form:
class classname //This denotes the base class of C++ virtual function
{
public:
virtual void virtualfunctioname() = 0 //This denotes the pure virtual function in C++
};
Question No: 32 ( Marks: 1 )
What is meant by direct base class ?
Ans
When a class-type is included in the class-base, it specifies the direct base class of the
class being declared. If a class declaration has no class-base, or if the class-base lists only
interface types, the direct base class is assumed to be object. A class inherits members
from its direct base class,
Deriving a class from more than one direct base class is called multiple inheritance.
Question No: 33 ( Marks: 2 )
Describe the way to declare a template class as a friend class of any other class.
Ans
The following example is use of a class template: eagle_eye
template<class L> class Key
{
L k;
L* kptr;
int length;
public:
Key(L);
// ...
};
Suppose the following declarations appear later:
Key<int> i;
Key<char*> c;
Key<mytype> m;
The compiler would create three objects.
Question No: 34 ( Marks: 2 )
What is the purpose of template parameter?
Ans:
There are three kinds of template parameters:
• type
• non-type
• template
You can interchange the keywords class and typename in a template parameter
declaration. You cannot use storage class specifiers (static and auto) in a template
parameter declaration.
Question No: 35 ( Marks: 3 )
Describe in simple words how we can use template specialization to enforce case
sensitive specialization in String class.
Ans”
The act of creating a new definition of a function, class, or member of a class from a
template declaration and one or more template arguments is called template instantiation.
The definition created from a template instantiation is called a specialization. A primary
template is the template that is being specialized.
create function objects to do the case-insensitive compares, and
then reuse them when also wanting to do case-insensitive sorting
or searching.
Question No: 36 ( Marks: 3 ) eagle_eye
fantasy.fear@gmail.com
Can we use compiler generated default assignment operator in case our class is using
dynamic memory? Justify your answer.
Ans:
the compiler does not make a separate copy of the object. Even if the types are not the
same, the compiler is usually able to do a better job with initialization lists than with
assignments.
Consider the following constructor that initializes member object x_ using an
initialization list: square::square() : x_(whatever) { }. The most common benefit of doing
this is improved performance. For example, if the expression whatever is the same type
as member variable x_, the result of the whatever expression is constructed directly inside
x_ — the compiler does not make a separate copy of the object. Even if the types are not
the same, the compiler is usually able to do a better job with initialization lists than with
assignments.
As if that wasn't bad enough, there's another source of inefficiency when using
assignment in a constructor: the member object will get fully constructed by its default
constructor, and this might, for example, allocate some default amount of memory or
open some default file. All this work could be for naught if the whatever expression
and/or assignment operator causes the object to close that file and/or release that memory
(e.g., if the default constructor didn't allocate a large enough pool of memory or if it
opened the wrong file).
Question No: 37 ( Marks: 3 )
Give the names of three ways to handle errors in a program.
Ans:
The function will throw DivideByZero as an exception that can then be caught by an
exception-handling catch statement that catches exceptions of type int. The necessary
construction for catching exceptions is a try catch system. If you wish to have your
program check for exceptions, you must enclose the code that may have exceptions
thrown in a try block.
The catch statement catches exceptions that are of the proper type. You can, for example,
throw objects of a class to differentiate between several different exceptions. As well,
once a catch statement is executed, the program continues to run from the end of the
catch.
the errors can be handled outside of the regular code. This means that it is easier to
structure the program code, and it makes dealing with errors more centralized. Finally,
because the exception is passed back up the stack of calling functions, you can handle
errors at any place you choose.
Question No: 38 ( Marks: 5 )
Consider the following code,
eagle_eye
fantasy.fear@gmail.com
class Base{
private:
void base1();
protected:
void base2();
public:
void base3();
};
class Derived: public Base{
private:
void derived1();
protected:
void derived2();
public:
void derived3();
};
int main(){
Derived * derived = new Derived();
return 0;
}
Fill the table below to tell which member functions of Base and Derived classes we
can access using the Derived pointer in the code indicated in bold.
Ans:
Function Name Availability (Yes / No)?
base2() no
base3() yes
derived1() No
derived2() No
derived3() Yes
Question No: 39 ( Marks: 5 )
What is the output produced by the following program?
#include<iostream.h>
void sample_function(double test) throw (int); eagle_eye
fantasy.fear@gmail.com
int main()
{
try
{
cout <<”Trying.\n”;
sample_function(98.6);
cout << “Trying after call.\n”;
}
catch(int)
{
cout << “Catching.\n”;
}
cout << “End program.\n”;
return 0;
}
void sample_function(double test) throw (int)
{
cout << “Starting sample_function.\n”;
if(test < 100)
throw 42;
}
Ans:
Starting sample_function
Trying
Trying after call
Catching
End program
Question No: 40 ( Marks: 10 )
Write a publicly derived class “Employee” that is derived from base class named
“Company”. Both classes will have function “create()”. Make virtual function of
base class and override same function in derived class. Function create will have an
output statement of your own choice.
In “main” Create an object of base class and call both functions with same object
type.
eagle_eye
fantasy.fear@gmail.com
Question No: 41 ( Marks: 10 )
Write a program in C++ which creates three classes named as
1. Equation
2. Linear
3. Quadratic
Where Linear and Quadratic are inherited from Equation
Each class has the method Graph. Graph method should be pure virtual in Equation class.
This method should be overridden in both the inherited classes. It is meant to display the
Graph shape of its respective class. Graph method of Linear will display the message;
Straight line
Similarly, the Graph method of Quadratic will display the message;
Parabola
In main, call the Graph method of both the Linear and Quadratic equations
polymorphically through the parent class (Equation).
Ans:
#include "fraction.h"
#include <iostream>
#include <string>
#include <string.h>
#include <stdlib.h>
class equation;
class equation {
int a, b;
public:
int c ()
{return (c);}
void convert (Cequation);
};
class linear {
private:
int side;
public:
void set_side (int a)
{side=a;}
friend class equation;
}; eagle_eye
fantasy.fear@gmail.com
void equation::convert (Cequation) {
a = 23;
b = 45;
}
int main () {
cequation sqr;
CRectangle rect;
sqr.set_side(4);
rect.convert(sqr);
cout << rect.area();
return 0;
}
COMPOSED BY SADIA ALI SADI (MBA)
www.vustudent.ning
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