UNIT I

What is C++? C++ is a general –purpose programming language with a bias towards system programming that - is a better C. - supports data abstraction - supports object-oriented programming

- supports generic programming.

Write the applications of C++? * C++ is a versatile language for handling very large programs.

* C++ is suitable for virtually any programming task including development of editors, compilers, databases, communication system and complex real-life application system. * C++ programs are easily maintainable and expandable.

Write the striking features of object oriented programming

1. Emphasis is one data rather than procedure.

2. Programs are divided into what are known as objects

3. Data structures are designed such that they characterize the objects.

4. Functions that operate on the data of an object are tied together in the data structure.

5. Data is hidden and cannot be accessed by external functions

6. Objects may communicate with each other through functions.

7. New data and functions can be easily added whenever necessary.

8. Follows bottom-up approach in program design.

What you mean by program paradigms?

Oject oriented programming is a technique for programming – a paradigm for writing “good” programs for a set of Problems. If the term “object-oriented programming language” means anything. It must mean a programming language that provides mechanisms that supports the object-oriented style of programming well.

What are the characteristics exhibited by procedure-oriented programming

1. Emphasis is on doing things (algorithms)

2. Most of the functions share global data.

3. Large programs are divided into smaller programs known as functions.

4. Data move openly around the system from function to function.

5. Functions transforms data from one form to another.

6. Employs top-down approach in program design.

What you mean by modular programming

A set of related procedures with the data they manipulate is often called a module. The programming paradigm becomes: Decide which module you want: partition the program so that data is hidden within modules. This paradigm is also known as the data hiding principle. Where there is no grouping of procedures with related date, the programming style suffices. Also , the technique for designing “good procedures” are now applied for each procedure in module. The most common example of module is the definition of stack.

What you mean by separate compilation?

C++ supports C’s notation of separate compilation. This can be used to organize a program into a set of semi-independent fragments. Typically , we place the declarations that specify the interface to a module in a file with a name indicating its intended use. Thus, namespace stack { void push(char); // interface char pop( ); } would be place in a file stack.h , and users will include that file, called a header file.

Write note on Exception handling. When a program is designed as a set of modules, error handling must be considered in right of these modules. Which module is responsible for handling what errors? Often, the module that detects an error doesn’t know what action to take. The recovery action depends on the module that involved the operation rather than on the module that found the error while trying to perform the operation.

Define user-defined types:

C++ attacks this problem by allowing a user to directly define types that behave in the same way as built-in types. Such a type is often called an abstract data type. A more reasonable definition of abstract data type would require a mathematical “abstract “ specification, what are called types here would be concrete examples of such truly abstract entities. The programming paradigm becomes: Decide which types you want: provide a full set of operations for each type.

Drawbacks of pop: * In pop Global data are more vulnerable to an inadvertent change by a function. * In a large program it is very difficult to identify what data is used by which functions. * In case we need to revise an external datastructures, we should also revise all functions that access the data, this provides an opportunity for bugs to creep in. * It does not model real world problems very well because functions are action-oriented and do not really correspond to the elements of the problem.

What are the characteristics incorporated by OOPS, write some languages that support these? Object-Oriented programming incorporates all of object –based programming features along with two additional features, namely, inheritance and dynamic-binding. Object-based features + inheritance + dynamic binding. Object based features * Data encapsulation * Data hiding and access mechanism * Automatic initialization & clear-up of objects

* Operator overloading Languages that supports these features include c++ , smalltalk & object pascal.

Depends upon features classify OOPS.

1. Object-based programming languages.

2. Object oriented programming languages.

State the following statements are true or false

i. In pop all data are shared by all functions.

---false.

(only global data can be shared by all functions)

ii. Inheritance means the ability to reuse the data values of one object by other objects ----True

iii. C++ allows us to create hierarchy-related objects---true d. In C++ , it is very easy to add to the existing structure of an object ---True.

Discuss cascading of I/O operators: The multiple use of <<in one statement is called cascading. When cascading an output operator, we should not ensure necessary blank spaces between different items.

a=10; b=15; cout << “A=”<<a<<”\n” << “B=” <<b<<”\n”; This is one statement but provides two lines of output. We can also cascade input operator >> as Cin>> number1>>number 2; The values are assigned from left to right.

State whether the following statements are true or

false

1. In C++ , Identifier name can be start with digit ----false

2. ::* is used to declare a pointer to a member of a class---true

3. (type –name) expression is type cast operator format in C++ ----false (It should be type-name (expression)

Discuss automatic conversion in C++. Whenever data types are mixed in an expression, C++ performs the conversions automatically. This process is known as implicit or automatic conversion.

SHORT CHAR Int Unsigned Long int

Unsigned long int Float Double

Long Double

Water fall model of type conversion

Find the errors, if any, in the following C++ statements

enum (green, yellow, red);
const int array-size;
int public =1000;
int* p = new; // allocate memory with new.

Discuss or compare the evolution of software technology. 1,0 MACHINE LANGUAGE ASSEMBLY LANGUAGE PROCEDURE PROGRAMMING OBJECT-ORIENTED PROGRAMMING Layers of software technology.
Write a short note on relationship of data and functions in a procedure- oriented program. GLOBAL DATA GLOBAL DATA FUNCTION – 1 FUNCTION – 2

FUNCTION – 3

LOCAL DATA LOCAL DATA LOCAL DATA In a multi function program, many important data items are placed as global, so that they may accessed by all function. Each function may its own local data.

20. Draw the program fragments representation: stack.h

stack interface user.c

stack.c

#include “stack.h” #include “stack.h”

use stack

define stack

UNIT II

21. What is meant by pointer to void?

The address that we put in a pointer must be the same type as the pointer. we cant assign the address of the float variable to a pointer to int. But there is an exception to this. There is a sort of general purpose pointer that can point to any data type called a pointer to a void.

E.g. Void *ptr ;

22. What are the uses of pointers?

Accessing array elements.
Passing arguments to a function when the function needs to modify the original arguments.
Passing arrays and string to functions.
Obtaining memory from the system.
Creating data structure such as linked lists.

23. What is the use of NEW and DELETE operator.

The NEW operator obtains a specified amount of memory from the system and returns a pointer to the memory. The operator is used to crate variables and data structure during program execution. The DELETE operator releases memory obtained by new.

24. Write a note on THIS pointer.

The member functions of every object have access to a sort magic pointer named this, which points to the object itself. Thus any member function can find out the address of the object of which is a member.

25. How serious is the breach of data integrity when friend functions are used?

A friend function must be declared as such within the class whose data it will access. Thus a programmer who does not have access to the source code for the class cannot make a function into a friend.

26. Write a note on friend function.

A friend function can access a class private data, even though it is not a member function of the class. This is useful when one function must have access to two or more unrelated classes and when an overloaded operator must use, on its left side, a value of a class other than one of which it is a member. Friends are also used to facilitate functional notation.

27. Define inline function.

An inline function looks like a normal function in the source file but inserts the function code directly into the calling program. Inline functions execute faster but may require more memory than normal functions unless they are very small.

28. Write a note on automatic variables.

Variables that are defined within a function body are called automatic variables. An automatic variable is not created until the function in which it is defined is called.

29. Define lifetime of a variable.

The time period between the creation and destruction of a variable is called the lifetime of the variable.

30. Define class.

Classes are created using the keyword class. A class declaration defines a new type that links code and data. This new type is then used to declare objects of that class an object is an instance of a class.

31. What are the 3 access specifiers and explain it.

The 3 access specifiers are Public, Private and Protected

· Private: It accessed only by other members of the class.

· Public: It allows functions or data to be accessible to other parts of programs.

· Protected: Access specifier is needed only when inheritance is involved.

32. Define Friend class.

It is possible to grant a non member function access to the private members of a class by using a friend. A friend function has access to all private and protected members of the class for which it is a friend.

33. How friend function can be declared.

To declare a friend function, include its prototype within the class preceding it with the keyword friend.

For eg,

Class myclass

{

int a,b;

public:

friend int sum(my class x);

};

34. What are the situations where inline expansion cannot work?

For function returning values, if a loop, a switch or a go to exists.
For function not returning values, if a return statements exist.
If function contain static variables.
If inline function are recursive.

35. How objects can be passed to function.

Objects may be passed to function in just the same way that any other type of variable can. Objects are passed to functions thru the use of standard call by value mechanism.

36. How objects can be returned in C++.

When an object is returned by a function a temporary object is automatically created that holds the return value. It is this object that is actually returned by the function.

37. How pointer can be used to derived type.

In general, a pointer of one type cannot point to an object of a different type.

However there is an important exception to this rule that relates only to derived class.

To begin assume two classes called B & D. that is D is derived from base class B. In this situation, a pointer of type B* may also point to an object of type D.

38. What is static member function and explain its characteristics?

A member function that is declared static has following property,

A static function can have access to only other static members declared in the same class.
A static member function can be called using the same class name as follows

class_name:: function_name;

39. What is scope resolution operator? Explain how does it work in c++?

The ::operator links a class name with a member name in order to tell the complier what class the member belongs to. It has another use that is it can allow access to a name in an enclosing scope that is hidden by a local declaration of the same name.

Egname.

Eg:

Void f()

{

int I;

I=10;

………..

……..

}

It may do so by preceding the I with the :: as shown here

Void f()

{

int I;

::I=10;

……..

}

40. How the pointer to the objects can be used in c++?

Just as we can have pointers to other types of variables, we can have pointers to objects. When accessing members of a class given a pointer to an object, use the arrow

(->) operator instead of the dot operator.

When pointer is incremented, it points to next element of its type. For eg: an integer pointer will point to next integer, in general, all pointer arithmetic is relative to base type of the pointer.

41. Define class and objects?

Classes are user defined data types and behave like the built in type of a programming languages. the wrapping up of data and functions into a single unit called class.

Objects are the basic run_time entities in an object oriented system. When a program is executed, the objects interact by sending messages to one another.

42. Compare and contrast between structure and class.

The only difference between a class and a structure is that by default all members are public in a struct and private in a class.

Comparisons:-

There is no fundamental reason not to increase the capabilities of a structure. In c structures already provide a means of grouping data. It also allows us to include member functions.

43. List the restrictions that are to be followed while using unions in c++

Union cannot inherit any other classes of any type.
Union cannot be a base class
No static variables can be members of a union
A reference member cannot be used
A union cannot have as a member any object that overloads = operator
No objects can be a member of a union if the object has an explicit constructor on destructor function.

44. Define friend function?

It’s possible to grant a non-member function access to the private members of a class by using the keyword friend. A friend function has access to all private and protected members of the class for which it is a friend.

45. Circumstances in which friend functions are quite valuable.

· Friends can be useful when you are overloading certain types of operators.

· Friend functions make the creation of some types of i/o functions easier.

· Two or more classes may contain members that are interrelated relative to other parts of our program.

46. Uses of inline functions.

Each time a function is called, a significant amount of overhead is generated by calling and return mechanism. Therefore it increases the performance of our program.

47. Static data member:-

A variable with a declaration static, tells the compiler that only one copy of that variable will exist and that all objects of the class will share the variable. No matter how many objects of a class are create. Only one copy of a static data member exists. Thus all objects of that class use that same variable. All static variables are initialized to zero before the first object is created.

48. Restrictions in using static member functions.

Static member functions can only directly refer to the other static members of the class.
Global data can also be accessed by static member’s functions.
Static member functions does not have a this pointer.
A static member functions may not be virtual.

49. Characteristics of friend function?

It is not in the scope of the class to which it has been declared as friend.

· Since it is not in the scope of the class. it cannot be called using the object of that class.

It cannot be invoked like a normal function without the help of any object
Usually it has objects as arguments.
It can be declared either in the public or private part of a class without affecting its meaning.

50. Arrays of objects:-

The objects that are created for a class can also be an array of objects.

Eg:-

Class employee

{

char name[10];

float age;

public:

void get(void);

void disp(void);

}ob[10];àarrays of objects

accessing:

for(I=1;I<=n;I++)

{

ob[i].get();

ob[i].disp();

}

51.What are the characteristics of member functions?

Several different classes can use the same function name.
Member functions can access the private data of the class except friend function.
A member function can call another member function directly, without using the dot operator.

52. What are the characteristics of Static member variable?

· It is initialized to zero, when the first object of its class is created. No other initialization is permitted.

· Only one copy of that member is created for the entire class and is shared by all the objects of that class.

· It is visible only within the class, but its lifetime is the entire program.

53. What are the properties of Static member functions?

· A Static function can have access to only other static members declared in the same class.

· A static member function can be called using the class name instead of its objects.

54. What are the advantages of using inline member functions?

· The size of the object code is considerably reduced.

· It increases the execution speed.

· The inline member functions are compact function calls.

55. What are the dynamic allocation operators?

New

· The new operator is used to create a heap memory space for an object of a class.

Delete

· The delete operator is used to destroy the variable space which has been created by using the new operator dynamically.

56. What are the restrictions that have been placed on Static member functions?

· Static member functions may only directly refer to other static members of the class.

· A static member function may only directly refer to other static members of the class.

· There cannot be static and a non-static version of the same function.

· A static member function may not be virtual.

· They cannot be declared as const or volatile.

57. What are the two ways to achieve call-by-reference parameter passing?

· Explicitly passing a pointer to the argument.

· Using a reference parameter.

58. What are the Restrictions to References?

· A Reference cannot be referenced or the address of a reference cannot be obtained.

· Array of reference cannot be created.

· A pointer to a reference cannot be created.

· A bit-field cannot be referenced.

· Null references are prohibited.

59. What are the 3 ways a reference can be used?

· As a function parameter.

· As a function return value.

· As a stand-alone reference.

60. What are the 2 ways in which arguments can be passed to functions?

· Call-by-value.

· Call-by-reference.

61. What is meant by this pointer?

When a member function is called, it is automatically passed an implicit argument that is a pointer to the invoking object. This pointer is called this.

62. What do local classes mean?

When a class is declared within a function, it is known only to that function and unknown outside of it. These types of classes are called local classes.

63. What are the restrictions to local classes?

· All member functions must be defined within the class declaration.

· The local class may not use or access local variables of the function which in which it is declared.

64. Ex plain what happens when constructors and destructor are executed?

In general an object’s constructor is called when the object comes into existence and an object’s destructor is called when the object is destroyed. Likewise when the object’s constructor function is executed, when the object’s declaration statement is encountered. The destructor functions for local objects are executed in the reverse order of the constructor functions.

65. What is the operator which is used to links the class name with member?

It is the scope resolution operator (::) which links the class name with a member name in order to tell the computer what class the member belongs to. It is also used to access the name in an enclosing scope that is hidden by a local declaration of same name.

Example:

int a; // global void f( )

{

int a; //local

a=10; //local

::a=10; //global

}

66. Write about initialized and un initialized array of objects.

We can create both initialized and un initialized array of objects. since it is a constructor it calls automatically by differentiating initialized and un initialized arrays.

Example:

Class cl
{

int a;

public:

cl( ) { a=0; }

cl(int j) { a=j; }\

};

cl a1[3] ={3,4,5}; // initialized

cl a2[10]; // uninitilized

67. How can we use objects as pointers.

Like we use pointers to other types of variables, we can have pointers to objects. when accessing members of class given a pointer to an object use the arrow(->) operator instead of the dot operator.

Example:

Class sample

{

int a;

public:

void print( ) { a=10*10 }

};

main( )

{

sample s,*p;

p=&s;

p->print( );

}

UNIT IV

68. Explain the concept of reusability in c++?

C++ strongly supports the concept of reusability. The c++ classes can be reused in several ways .Once a class has been written and tested, it can be adapted by other programmers to suit their requirement .this done by creating new class reusing the properties of the existing ones is called reusability,

69. Explain the concept of inheritance?

Creating a new classes, reusing the properties of the existing ones ,this mechanism of deriving a new class from old one is called inheritance or derivation. The old class is referred to as the bare class and the new one is called the derived class or subclass.

70. Explain briefly the different forms of inheritance?

There are 5 forms available, namely

· Single inheritance: A derived class with only one base class

· Multiple inheritance: A derived class with only several base class

· Hierarchical inheritance: The traits one class may be inherited by more than one class

· Multilevel inheritance:

· Hybrid inheritance: it is a combination of multiple and hierarchical inheritance.

71. Define Derived class?

A derived class can be defined by specifying its relationship with the base class in addition to its own details. the general form of defining a derived class is

Class derived_class_name

{

--------------

--------------//members of derived class

--------------

};

71. What is meant by visibility mode explain briefly?

Visibility mode is optional and may be either private or public. The default visibility mode is private. Visibility mode specifies whether the features of the base class are privately derived or publicly derived.

Eg:

Class abc: private Xyz // private derivation

{

members of abc;

};

Eg : 2

Class abc: private Xyz // public derivation

{

members of abc;

};

72. What is a virtual function?

A C++ member function that is declared with the keyword virtual. The implementation that is executed when you make a call to a virtual function depends on the type of the object for which it is called. This is determined at run time.

73. Why do we need virtual function?

When a function is made virtual, c++ determines which function to use at run time based on the type of object pointed to by the base pointer, rather than the type of the pointer. By making the base pointer to point to different objects, we execute different versions of the virtual function.

74. What is meant by pure virtual function?

A virtual function, equated to zero is called a pure virtual function. It is a function declared in a base class that has no definition related to the base class.

e.g.: virtual void display () =0;

75. What is meant by abstract class specify its objective?

A virtual function, equated to zero is called a pure virtual function. It is a function declared in a base class that has no definition relative to the base class. A class containing such pure function is called an abstract class.

It objectives are

· Provide some traits to the derived classes.

· To create a base pointer required for achieving run time polymorphism.

76. Write some of the rules for virtual function?

1. Virtual functions must be members of some class.

2. They cannot be static members.

3. They are accessed by using object pointers.

4. A virtual function can be a friend of another class.

5. We cannot have virtual constructors but we can have virtual destructors.

6. If a virtual function is defined in the base class. It need not be necessarily redefined in the derived class.

77. What does generic programming means?

Templates execute us to define generic class and functions and thus provides support for generic programming. It is an approach where generic types are used as parameters in algorithms so that they work for a veriety of suitable data types and data structures.

78. Why do we call templates as a parameterized class?

Templates are defined with a parameter that would be replaced by a specified data type at the time of actual use of the class or function, the template are some times called as parameterized classes or functions.

79. Define template class?

A class created from a class template is called a template class. The syntax for defining an object of a template class is :

Class_name<type>object_name(arglist);

This process of creating a specific class from a class is called instantiation. The compiler will perform the error analysis only when an instantiation takes place.

80. Define class templates with multiple parameters?

We can use more than one generic data types in a class template. They are declared as a comma separated list within the template specification as show below:

Syntax:

Template<class t1, class t2, ..>

Class classname

{

----------

---------- ( body of the class)

};

81. Define function templates?

Like class template we can also define function templates that would be used to create a family of function with different argument types.

Syntax:

Template<class T>

return type function name(argument of type T)

{

………..

//body of function

//with type T

//wherever appropriate

}

We must use the template parameter T as and when necessary in the function body and in its arguments list.

82. Explain function templates with multiple parameters?

Like template class we can use more than one generic data type in the template statement, using comma separator

Syntax:

Template<class T1,class T2,….>

return type function name(argument of type T1,T2,…)

{

………..

//body of function

}

83. How can we overload a template functions?

A template function may be overloaded either by template function or by ordinary function of its name. in such cases the overloading resolution is accomplished by

· Call an ordinary function that has an exact match.

· Call a template function that would be created with an exact match.

· Try normal overloading resolution to ordinary function and call the one that match.

84. What is meant by member function template?

The member functions of the template classes themselves are parameterized by the type argument and therefore there function must be defined by the function template.

Syntax:

Template<class T>

return type classname<T> : : function name(arglist)

{

……………(function body)

…………….

}

85. Explain non-type template arguments?

It is also possible to use non type arguments that are in additional argument T, we can also use other arguments such as strings, function names, constant expressions and built-in types.

Eg:

Template<class T, int size>

Class array

{

T a[size];

……..

};

this templates supplies the size of the array as an argument.

86. Benefits of templates?

· Templates allow implementing the concept of generic programming.

· Template allows us to generate a family of classes or a family of functions to handle different data types.

· Template classes and functions eliminate code duplication for different types and thus make the program development easier and more manageable.

· We can use multiple parameters in both the class templates and function templates.

· Like other functions templates can be overloaded.

87. What is meant by exception?

Some peculiar problems other than logic or syntax errors, they are known as exceptions. Exceptions are run time anomalies or unusual conditions that a program may encounter while executing. Anomalies might include condition such a division by zero, array outside of its bound etc.

88. Explain the various types of exceptions?

They are of two kinds:

1. synchronous exception

2. Asynchronous exception.

Synchronous exception:

Errors such as “out of range index” and “over flow” belong to synchronous type exception.

Asynchronous exception:

Errors that are caused by event beyond the control of the program are called asynchronous exception.

Note:

Proposed exception handling mechanism in c++ is assigned to handle only synchronous exception.

89. Define exception handling mechanism?

Exception handling mechanism is basically built upon through keywords namely try, catch, and throw. The keyword try is used to preface a block of statements which may generate exception. This block of statements is known as try block. When an exception is detected, it is thrown using a throw statement in the try block. A catch statement is defined by the keyword catch “catches” the exception thrown by the throw statement in the try block.

Diagrammatic representation

90. Purpose of the exception handling?

The purpose of exception handling mechanism is to provide means to detect and report an “exception circumstance”. So that appropriate action can be taken. The mechanism suggests a separate error handling code that performs the following tasks.

Find the problem (hit the exception).
Inform than an error has occurred (throw the exception).
Receives the error information (catch the exception).
Take corrective action (handle the exception).

91. Explain throwing mechanism briefly?

When an exception that is desired to be handled is detected, it is thrown using throw statement in one of the following forms:

Throw(exception)

Throw exception;

Throw; // used for rethrowing an exception.

92. Explain multiple catch statements?

It is possible that a program segment has more than one condition to throw an exception. In such case we can associate more than one catch statement with a try. For eg:

Try

{

//try block;

}

catch (type 1 arg)

{

// catch block1;

}

catch (type 2 arg)

{

// catch block 2;

}

……………….

Catch (type n arg)

{

// catch block n;

}

93. Explain briefly about rethrowing an exception?

A handler may decide to rethrow the exception caught without processing it. In such situation, we may simply invoke throw without any argument.

Eg: throw;

This cause the current exception to be thrown to the next enclosing try/catch sequence and is caught by a catch statement listed after that enclosing try block.

94. What is STL? What are its three components?

A collection of generic classes and function is called the standard template library (STL). STL components are part of c++ standard library. STL consist of three main components. They are

· Containers

· Algorithms

· Iterators

95. What is meant by container?

A container is an object that actually stores data. It is a way data is organized in memory, the STL containers are implemented by template classes and therefore can be easily customized to hold different types of data.

96. What is meant by algorithm?

An algorithm is a procedure that is used to process the data contained in the containers. The STL includes many different kinds.

97. Define map?

A map is a sequence of key value pairs that provides for fast retrieval based on the flag. Almost one value is held for each key; in other words, each key in a map is unique.

98. What is a multimap?

A multimap is a map, except that it allows duplicate keys. Naturally several values can exist for a single key. A multimap is preferred over a map. In some ways, a multimap is even cleaner and more elegant than a map.

99. How is an iteration over a map is carried out?

Iteration over a map is simply iteration over a sequence of pair < const key, mapped_type >. For e.g. We might print out the entries of a phone book like this

Void f(map<string, number>& phone_book) {

Typedef map(string, number)::const_iteration CI;

For(CI =phone_book.begin( ); p!=phone_book.end( );++p)

cout<<p->first<<’\t’<<p->second<<’\n’;

}

A map iterator presents the elements in ascending order of its keys.

100. What is a predicate?

A predicate is a function object (or a function) that returns a bool.

101. Define function object?

An object of a class with an application operator is called a function. Like object, a function or simply functions object. Consequently, function objects often execute faster than do ordinary function.

(or)

An object that acts like a function is often called function like object (or) simply function. Such function objects are important because they allow us to write code that takes operations as parameters.

102. What are arithmetic function objects?

When dealing with numeric classes, it sometimes useful to have the arithmetic function available as function objects. Consequently the standard library provides arithmetic operations.

<functional

plus binary arg1 + arg2

minus binary arg1 - arg2

multiplies binary arg1 * arg2

divides binary arg1 / arg2

modules binary arg1 % arg2

negate Unary -arg1

103. Define Non-modifying sequence algorithm?

These algorithms are provided to do the most common forms of updates. Some update a sequence while others produce a new sequence based on information found during a traversal.

Std. algorithm work on data structures thru Iterators. This implies that inserting a new element into a container (or) deleting one is not easy.

104. Define binder.

A binder allows a two-argument function object to be used as a single-argument function by binding one argument is a value.

105. What are member function adapter & pointer to function adapter?

A member function adapter allows a member function to be used as an argument to algorithms.

A pointer to function adapter allows a pointer to function to be used as an argument to algorithm.

106. Define container.

A container is an object that actually stores data. It is a way data is organized in memory .The STL container are implemented by template classes and therefore can be easily customized to hold different types of data .

107. Define an algorithm.

An algorithm is a procedure that is used to process the data contained in the containers. The STL includes many different kinds of algorithm to provide support to task such as initializing; searching, copying, sorting and merging. Algorithm is implemented by template functions.

108. Define Iterators.

Iterators are an object that points to an element in a container .We can use Iterators to move through the contents of containers. Iterators are handled just like pointers. We can increment or decrement them.Iterators connect algorithm with containers and play a key role in the manipulation of data stored in the containers.

109. What are the types of Iterators that are supported by each container class?

There are three major categories of containers:

Sequence container

1) Vectors

2) Dequeue

3) list

Associative container

1. set

2. multiset

3. map

4. multimap

Derived container

1. stack

2. queue

3. priority queue

110. Define sequence container?

Sequence container stores elements in a linear sequence like a line .Each elements are related to other by its position along the line. They all expand themselves to allow insertion to the elements and all of them support a number of operations on them.

Element0àElement1àElement2à……..àLast element…

Begin() end()

111. Define associative container?

Associative containers are designed to support direct access to elements using keys. They are not sequential. There are 4 types of container:

set
multiset
multimap
map

All these containers stores data in a structure called tree which facilities fast searching, deletion and insertion.

112. Define derived container?

The STL provides three derived containers namely:

Stack, queue and priority queue. These are known as Container adaptors.

These can be created for different sequence container and it does not support the Iterators and therefore we cannot use them for data manipulation.

However, they support two member functions pop() and push() fro implementing deleting and inserting operation.,

113. What is meant by algorithm?

Algorithms are function that can be used generally across a variety of containers for processing their contents.

114.What is meant by STL algorithm?

STL algorithm rein force the philosophy of reusability. By using these algorithms, programmers can save a lot of time and effort.

To access STL Algorithm we must included <algorithm> in our program.

115. What are the categories of STL algorithm?

STL algorithm based on the nature of operations it may be categorized s follows:

retrieve or non-mutating algorithm
Mutating algorithm
Sorting algorithm
Set algorithm
Relational algorithm

116. What is meant by list?

The list is another container that is popularly used. It supports bidirectional, linear list and provides an efficient implementation for deletion and insertion operation. Unlike a vector, which supports random access, a list can be accessed sequentially only.

Write some important member functions of the list class?

function	Task
Back()	Gives a reference to the last element
Begin()	Gives a reference to the first element
Clear()	Deletes all the elements
Empty()	Decides if the list is empty or not
End()	Gives refernce to the end of the list
Erase()	Deletes elements as specified
merge()	Merge two ordered list
Insert()	Insert elemements as specified
Pop_back()	Deletes the last element
Pop_front()	Deletes the first element
Push_back()	Adds an element at the end
Push_front()	Adds an element at the front
Remove()

UNIT V

117. What are the kinds of classes?

· Concrete types

· Abstract types

· Nodes

· Operations

· Interfaces

· Handles

· Application frameworks

These kinds of classes are design notion and not language constructs.

118. What is meant by concrete types?

Classes such as vector, list, date and complex are concrete in the sense that each is the representation of a relatively simple concept with all the operations essential for the support of that concept.

Each has a one to one correspondence between its interface and an implementation and none are intended as a base for derivation.

119. What are the aims of concrete types?

The aims of concrete type classes are:

i. To be a close match to a particular concept and implementation strategy.

ii. To provide run time and space efficiency comparable to hand crafted code through the use of in-lining and of operations taking full advantage of the properties of the concept and its implementation.

iii. To have only minimal dependency on other classes; and

iv. To be comprehensible and usable in isolation.

v. Providing a clear and efficient representation of a single concept.

120. what are the important points to remember while using concrete types?

i. Concrete types are fitted into a hierarchy of related classes.

ii. Each concrete type can be understood in isolation with minimal reference to other classes.

iii. If a concrete type is implemented well, programs using it are comparable in size and speed to programs a user would write using a hand-crafted and specialized version of the concept.

iv. If the implementation changes significantly the interface is usually modified to reflect the change.

v. Concrete type resembles in the built in type.

121. What are the advantages of concrete type over abstract type?

i. An individual concrete classes is easier to understand and use then is a more general class.

ii. Concrete type is often used for classes that represent well known data types such as arrays and list.

122. What is meant by abstract type?

i. A class is said to be abstract class that represents the interface to a set of implementations of a common concept.

ii. The abstract class provides the common interface to the implementation. This means, we can use a set without knowing which kind of implementation is used.

123. Differentiate between concrete type and abstract type.

Concrete type	Abstract type
* We require a redesign of the implementation classes to express commonality and issued a template to exploit it.	* Design a common interface but no commonality beyond re-ability to implement the interface.
* If the implementation changes significantly the interface is usually modified to reflect the change.	Users need not depend on these declarations and need not be recompiled or in any way changed if set changes.

124. What are the aims of abstract types?

i. Define a single concept in array that allows several implementations of it to coexist in a program.

ii. Provide reasonable run-time and space efficiency through the use of virtual functions .

iii. Each implementation have only minimal dependency on other classes.

iv. Comprehensible in isolation.

125. Why do we have concrete types when we have abstract type?

i. Efficiency : - We want to have concrete types such as vector and list without the overheads implied by decoupling the implementations from the interfaces.

ii. Reuse : - We need a mechanism to fit types designed elsewhere into a new library or application by giving them a new interface.

iii. Multiple interfaces : - Using a single common base fro a variety of classes leads to fat interfaces. Often it is better to provide a new interface to a class for new purposes rather than modify its interface to serve multiple purposes.

126. Define node class.

A node class relies on services from base classes to provides its own services. That is, it calls base class member functions. Atypical node class provides not just an implementation of the interface specified by its base class. It also adds new functions itself, thus providing a wider interface.

127. What are the important functions of node class?

The important functions are the constructor through which the programmer specifies the basic properties that are relevant to the simulation and the virtual functions that allow the simulation routines too manipulate a public variable without knowing its exact type.

128. What are the aims of node classes.

i. relies on its base classes both for its implementation and for supplying services to its users.

ii. Provides a wider interface (i.e an interface with more public members) to its users than do its base classes.

iii. Relies primarily on virtual functions in its public interface.

iv. Depends on all of its( direct and indirect) base classes.

v. Can be understood only in the contest of its base classes.

vi. Can be used as a base for further derivation.

vii. Can be used to create objects.

129. What is meant by concrete node types?

A class that does not confirm to point base for further derivation resembles on concrete type and could be called as concrete node types.

130. What is meant by leaf classes?

A concrete node class can be used to implement an abstract class and variables of such a class can be allocated statically and on the stack. Such a class is sometimes called as leaf class.

131. What is meant by abstract node class?

A class that does not confirm to create objects resembles on abstract type and it is called as abstract node types.

132. What is meant by node classes?

i. A node classes is a part of the class hierarchy.

ii. A class hierarchy is built with a view of derivation different from the interface/implementer view used for abstract types.

iii. A class is viewed as a foundation on which to build even if it is an abstract class, it usually has some representation and provides some services for its derived classes. Example of node classes are polygon, Ival _slider and satellite.

133. What are the uses of changing interface?

i. These techniques can be used to invoke a function based on a string supplied by a user.

ii. To manipulate objects of unknown type through interfaces discovered through run-time type identification.

134. Define changing interfaces.

By definition, a node class is part of a class hierarchy. Not every class in a hierarchy needs to offer the same interface. In particular, a derived class can provide more member functions, and a sibling class can provide a completely different set of functions.

135. Define action.

The simplest and most obvious way to specify an action in C++ is to write a function. If an action has to be delayed, it has to be transmitted elsewhere before being performed, it requires its own data that has to be combined with other actions etc.,

Then is often becomes attractive to provide the action in the form of a class that can execute the desired action and provide other services as well.

136. What is meant by interface classes?

i. An interface class doesn’t do much – if it does then it is not an interface class.

ii. It simply adjusts the appearance of some service to local needs.

iii. Interface classes are essential to allow sharing without forcing all users into a common straitjacket.

137. What are the uses of interface classes?

i. A major use of interface function is to adjust interface to match users exceptions better, thus moving code that would have been scattered throughout a users code into an interface.

ii. An interface class that controls access to another class or adjusts its interface and is sometimes called as wrapper.

iii. Interface classes is to provide checked or restricted interfaces.

138. What is handle classes?

i. A handle providing the user interface and a representation holding all or most of the object’s state.

ii. The connection between the handle and the representation is typically a pointer in the handle.

iii. Handles have a bit more data than the simple representation, but not much more.

iv. The layout of a handle is typically stable even when the representation changes and also that handles are enough to move around relatively freely so that pointer and references need not be used by the user.

139. Explain the uses of handling classes.

i. It is useful to extract the representation pointer from a handle and use it directly.

ii. It works nicely provided the called function does not destroy the object passed to it.

140. What are the operations in handles?

i. Overloading -> enables a handle to gain control and do some work on each access to an object.

ii. Handles for which work needs to be done both before and after access require more elaborate programming.

141. Define application frameworks.

A more ambitious approach to the support of design and reuse is to provide code that establishes a common framework into which the application builder fits application – specific code as building blocks. Such an approach is often called as application frameworks.

142. What are the uses of application frameworks?

i. A framework to be of significant use, it must provide more structure and many more services than this simple example does.

ii. A framework will also be supported by a library that provides classes that are useful for the application programmer when specifying the action classes.

143. What is wrapper?

An interface class that controls access to another class or adjusts its interface and is sometimes called as wrapper.

144. What are the two parts to separate a single object?

These issues is to separate a single object into two parts.

i. A handle providing the user interface.

ii. A representation holding all or most of the object’s state.

145. What is used as a connection between handle and the representation?

The connection between the handle and the representation is typically a pointer in the handle.

146. What is called proxy?

A handle that provides an interface that is close to identical to the class for which it is a handle often called as proxy.

147. How a base class is defined in handles?

i. Idea is to have one handle class for a family of classes defined by a base class.

ii. Derivation from this base class can be a powerful technique.

iii. It appears to a node class and abstract types.

148. How does the overloading function performs in handles?

Overloading -> enables a handle to gain control and do some work on each access to an object.

149. Which approach is called application framework?

An approach to the support of design and reuse is to provide code that establishes a common framework into which the application builder fits application – specific code as building blocks. Such an approach is often called as application frameworks.

UNIT III

1. Define function overloading.

Two or more functions can share the same name that perform a variety of different tasks as long as their parameter declarations are different. The functions that share the same name are said to be overloaded, and the process is referred to as function overloading.

2. When the functions are said to be overloaded?

Functions are said to be overloaded when they have same name with different number and the type of the arguments. Two functions differing only in their return types cannot be overloaded.

3. Write a note on default arguments.

C++ allows us to call a function without specifying all its arguments. In such cases, the function assigns a default value to the parameter that does not have matching arguments in the function call. Default values are specified when the function is declared. We must add the defaults from right to left.

4. Mention the advantages of providing the default arguments.

· We can use default arguments to add new parameters to

the existing functions.

· Default arguments can be used to combine similar

functions into one.

5. Mention the advantages of having default arguments in constructors.

· It prevents us from having to provide an overloaded

constructor that takes no parameters.

· It is convenient by providing the default common initial

values than specifying them each time an object is declared.

6. Explain overloading the new operator.

Syntax:

Void *operator new(size_t size)

{

/*performs the allocation operation.

Constructor is called automatically.

returns pointer to memory*/ }

size_t - It is a defined type capable of containing the largest single piece of memory that can be allocated.

Size - It contains the number of bytes needed to hold the object being allocated.

When we allocate an object using new, the object’s constructor is automatically called.

7.Explain overloading the delete operator.

Syntax:

Void operator delete(void *p)

{

/*free memory pointed to by p.

destructor is called automatically.*/

}

The delete function receives a pointer to the region of memory to be freed. It then releases the previously allocated memory back to the system. When an object is deleted, its destructor is automatically called.

8. What is constructor overloading?

When there is more than one constructor in a class with different parameters and with different data types we say that the constructor is overloaded.

9. What is constructor?

A constructor is a special member function whose task is to initialize the objects of its class. It is special because its name is the same as the class name. The constructor is invoked whenever an object of its associatied class is created.

It is called constructor because it construct the values of data members of the class.

10. How to declare and define constructor?

A constructor is declared and defined as

Class integer

{

int m,n;

public:

integer(void); //constructor declared

……….

………..

};

integer : : integer(void)//constructor defined

{

m=0;

n=0;

}

11. what are properties of the constructor function?

The constructor functions have some properties:

· they should be declared in the public section.

· They are invoked automatically when the objects are created.

· They do not have return types,not even void and therefore,they cannot return values.

· They cannot be inherited, through a derived class can call the base class constructor.

· Like other c++ functions,they can have default arguments.

· Constructors cannot be virtual.

· We cannot refer to their addresses.

· An object with a constructor cannot be used as a member of a union.

· They make implicit calls to the operators new and delete when memory allocation is required.

· When a constructor is declared for a class, initialization of the class objects becomes mandatory.

12. what are characteristics of the constructor function?

The constructor functions have some characteristics:

· they should be declared in the public section.

· They are invoked automatically when the objects are created.

· They do not have return types,not even void and therefore,they cannot return values.

· They cannot be inherited, through a derived class can call the base class constructor.

· Like other c++ functions,they can have default arguments.

· Constructors cannot be virtual.

· We cannot refer to their addresses.

· An object with a constructor cannot be used as a member of a union.

· They make implicit calls to the operators new and delete when memory allocation is required.

When a constructor is declared for a class, initialization of the class objects becomes mandatory.

13. list types of constructor?

5 types of constructor

a. default constructor(or)empty constructor

b. default argument constructor

c. constructor polymorphism(or)multiple constructor(or)constructor overloading

d. copy constructor

e. parameterized constructor.

14.what is default constructor.give example?

A constructor that accepts no parameters is called the default constructor. The default constructor for class A is A::A( ). If no such constructor is defined, then the compiler supplies a default constructor. Therefore a statement such as

A a;

Invokes the default constructor of the compiler to create the object a.

15.what is parameterized constructors,give example?

It may be necessary to initialize the various data elements of different objects with different values when they are created.

C++ permits us to achieve this objective by passing argument to the constructor function when the objects are created. The constructors that can take arguments are called parameterized constructors.

Eg:

Class A

{

int m,n;

public:

A(int x,int y); //parameterized constructor

………..

};

A : : A(int x,int y)

{

m=x;

n=y;

}

16.what are the two ways to pass values as arguments to the constructor?

Two ways to pass values as arguments to the constructor function when an object is declared.

By calling the constructor explicitly.

By calling the constructor implicitly.

Eg :

Explicit call:

Integer int1=integer(0,200);

Implicit call:

Integer int1(0,100);

17.How to pass values as arguments to the constructor when an object is declared?

To pass values as arguments to the

constructor function when an object is declared. This done in two ways.

1. By calling the constructor explicitly.

2. By calling the constructor implicitly.

Eg :

Explicit call:

Integer int1=integer(0,200);

Implicit call:

Integer int1(0,100);

18.which method is called as shorthand method?

To pass values as arguments to the

constructor function when an object is declared.

By calling the constructor implicitly

Eg:

Implicit call:

Integer int1(0,100);

This method is called as shorthand method,is used very often as it is shorter,looks better and is easy to implement.

19.what is default argument constructor?

It is possible to define constructors with default arguments . for example,the constructor complex( ) can be declared as follows:

Complex(float real,float imag=0)

The default value of the argument imag is zero.then the statement

Complex c(5.0);

Assigns the value 5.0 to the real variable and 0.0 to imag (by default). However, the statement

Complex c(2.0,3.0);

Assigns 2.0 to real and 3.0 to imag. The actual parameter, when specified, overrides the default value. As pointed out earlier, the missing arguments must be the trailing ones.

20.Distinguish between default constructor and default argument constructor?

Default constructor	Default argument construtor
1. the constructor that accepts no parameter is called is default constructor. 2.it is used in class by A :: A( )	1.the default argument constructor can be called with either one argument or no arguments. 2.it is used in class by A:: A(int =0)

21.Discuss on copy constructor?

Copy constructor is used to declare and initialize an object from another object.

For example, the statement

Integer I2(I1);

Would define the object I2 and at the same time initialize it to the values of I1. another form of this statement is integer I2=I1;

The process of initializing through a copy constructor is known as copy initialization. A copy constructor takes a reference to an object of the same class as itself as an argument.

22.What is dynamic constructor?

The constructor can also be used to allocate memory while creating objects.

This will enable the system to allocate the right amount of memory for each object when the objects are not of the same size,thus resulting in the saving of memory;. Allocation of memory to object at the time of their construction is known as dynamic construction of objects. The memory is allocated with the helop of the new operator. The useo of new in construcors that are used to construct strings in objects.

23. Discuss on destructors?

A destrucor, as the name implies, is used to destroy the objects that have been created by a constructor. Like a constructor, the destructor is a member function whose name is the same as the class name but is preceded by a tilde. For example, the destructor for the class integer can be defined

~integer(){}

A destructor never takes any argument nor does it return any value. It will be invoked implicity by the compiler upon exit from the program to clean up storage that is no longer accessible. It is a good practice to declare destrucors in program since it releases memory space for future use.

24.Difference between constructor and destructor?

constructor	destructor
1.Constructor is a ‘special’ member function whose task is to initialize the objects of its class. 2. it construct the values of data members of the class	1.destructor is a member function whose name is the same as the class name but is preceded by a tilde. 2. it destroy the objects that have been created by a constructor.

25.How to use delete operator in destructor?

Whenever new is used to allocate memory in the constructors.we should use delete to free that memory. For example , the destructor for the matrix class discussed above may; be defined as follows

Matrix :: ~matrix( )

{

for(int i=0;i<d1;i++)

delete p[i];

delete p;

}

26.what is multiple constructor?

The sharing the same name by wo or more functions is referred to as function overloading. Similarly when more than one constructor function is defined in a class. We say that the constructor is overloaded. It is also called multiple constructor.

Example :

Complex() { } //constructor with no arg.

Complex (float a) { x=y=a;} //constructor with one arg.

Complex (float real, float imag) //constructor with two arg.

27.What is overloading constructor?

Example :

Complex() { } //constructor with no arg.

Complex (float a) { x=y=a;} //constructor with one arg.

Complex (float real, float imag) //constructor with two arg.

28.How to initialize object dynamically?

Class objects can be initialized dynamically too. That is, the initial value of an object may; be provided during run time.

Advantages:

We can provide various initialization formats, using overloaded constructor. This provides the flexibility of using different format of data at run time depending upon the situation.

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Tuesday 22 February 2011

C_PLUS_PLUS_TWO_MARKS_PART_I

UNIT II

Class sample

UNIT IV

Concrete type

Abstract type

UNIT III

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