Key Points - Object Oriented Programming Concepts

Object Oriented Programming follows bottom up approach in program design and emphasizes on safety and security of data..

FEATURES OF OBJECT ORIENTED PROGRAMMING:

Inheritance:- 
Inheritance is the process of forming a new class from an existing class or base class. The base class is also known as parent class or super class.
Derived class is also known as a child class or sub class. Inheritance helps in reusability of code , thus reducing the overall size of the program
Data Abstraction:It refers to the act of representing essential features without including the background details .Example : For driving , only accelerator, clutch and brake controls need to be learnt rather than working of engine and other details.

Data Encapsulation:- 
It means wrapping up data and associated functions into one single unit called class..
A class groups its members into three sections :public, private and protected, where private and protected members remain hidden from outside world and thereby helps in implementing data hiding.

Modularity: - - 
The act of partitioning a complex program into simpler fragments called modules is called as modularity.
It reduces the complexity to some degree and
It creates a number of well defined boundaries within the program .
Polymorphism:- Poly means many and morphs mean form, so polymorphism means one name multiple forms.
It is the ability for a message or data to be processed in more than one form.
C++ implements Polymorhism through Function Overloading , Operator overloading and Virtual functions.
.
SHAPE area
RECTANGLE arearectangle
TRIANGLE
CIRCLE
Area triangle
Area circle

1. Objects and Classes: The major components of Object Oriented Programming are . Classes & Objects
A Class is a group of similar objects . Objects share two characteristics: They all have state and behavior. For example : Dogs have state name, color, breed, hungry and behavior barking, fetching, wagging tail. Bicycles also have state current gear, current pedal cadence, current speed) and behavior changing gear, applying brakes). Identifying the state and be havior for realworld objects is a great way to begin thinking in terms of object-oriented programming. These real-world observations all translate into the world of object-oriented programming.
Software objects are conceptually similar to real-world objects: they too consist of state and related behavior. An object stores its state in fields variables in some programming languages) and exposes its behavior through functions

Classes in Programming: -  It is a collection of variables, often of different types and its associated functions.
-  Class just binds data and its associated functions under one unit there by enforcing encapsulation.
-  Classes define types of data structures and the functions that operate on those data structures.
-  A class defines a blueprint for a data type.
Declaration/Definition: A class definition starts with the keyword class followed by the class name; and the class body, enclosed by a pair of curly braces. A class definition must be followed either by a semicolon or a list of declarations. class class_name { access_specifier_1: member1; access_specifier_2: member2;
...
} object_names;
Where class_name is a valid identifier for the class, object_names is an optional list of names for objects of this class. The body of the declaration can contain members that can either be data or function declarations, and optionally access specifiers.
[Note: the default access specifier is private.
Example : class Box { int a; public: double length; // Length of a box double breadth; // Breadth of a box double height; // Height of a box
};

1. Access specifiers in Classes:
Access specifiers are used to identify access rights for the data and member functions of the class.

There are three main types of access specifiers in C++ programming language:- 
-  private public protected
Member-Access Control
Type of Access
Meaning
Private
Class members declared as private can be used only by member functions and friends classes or function s) of the class.
Protected
Class members declared as protected can be used by member functions and friends (classes or functions) of the class. Additionally, they can be used by classes derived from the class.
Public
Class members declared as public can be used by any function.
-  Importance of Access Specifiers
Access control helps prevent you from using objects in ways they were not intended to be used. Thus it helps in implementing data hiding and data abstraction.

OBJECTS in C++:
Objects represent instances of a class. Objects are basic run time entities in an object oriented system.
Creating object / defining the object of a class:
The general syntax of defining the object of a class is:Class_name object_name;
In C++, a class variable is known as an object. The declaration of an object is similar to that of a variable of any data type. The members of a class are accessed or referenced using object of a class.
Box Box1;
Box Box2;
// Declare Box1 of type Box
// Declare Box2 of type Box
Both of the objects Box1 and Box2 will have their own copy of data members.
Accessing / calling members of a classAll member of a class are private by default.
Private member can be accessed only by the function of the class itself.Public member of a class can be accessed through any object of the class. They are accessed or called using object of that class with the help of dot operator (..

1. The general syntax for accessing data member of a class is:Object_name.Data_member=value;
The general syntax for accessing member function of a class is:Object_name. Function_name (actual arguments);
The dot ('. ' used above is called the dot operator or class member access operator. The dot operator is used to connect the object and the member function. The private data of a class can be accessed only through the member function of that class.
Class methods definitions Defining the member functions
Member functions can be defined in two places:- 
Outside the class definition
The member functions of a class can be defined outside the class definitions. It is only declared inside the class but defined outside the class. The general form of member function definition outside the class definition is:
Return_type Class_name:: function_name argument list
{
Function body
}
Where symbol :: is a scope resolution operator.
The scope resolution operator :: specifies the class to which the member being declared belongs, granting exactly the same scope properties as if this function definition was directly included within the class definition class sum
{ int A, B, Total; public: void getdata (; void display (;
}; void sum:: getdata (
// Function definition outside class definition Use of :: operator
{ cout<<” n enter the value of A and B”; cin>>A>>B;
} void sum:: display
// Function definition outside class definition Use of :: operator
{
Total =A+B; cout<<” n the sum of A and B=”<<Total;
}
1. - 
Inside the class definition
The member function of a class can be declared and defined inside the class definition. class sum
{ int A, B, Total; public: void getdata (
{ cout< ” n enter the value of A and B”; cin>>A>>B;
} void display (
{ total = A+B; cout<<” n the sum of A and B=”<<total;
}
};

Differences between struct and classes in C++
In C++, a structure is a class defined with the struct keyword.Its members and base classes are public by default. A class defined with the class keyword has private members and base classes by default. This is the only difference between structs and classes in C++.

INLINE FUNCTIONS
-  Inline functions definition starts with keyword inline
-  The compiler replaces the function call statement with the function code itselfexpansion and then compiles the entire code.
-  They run little faster than normal functions as function calling overheads are saved.
-  A function can be declared inline by placing the keyword inline before it.
Example inline void Square (int a
{ cout<<a*a;} void main(
{.
Square4);
Square8)
{ cout <<4*4;}
;
{ cout <<8*8; }
In place of function call , function body is substituted because
Square ( is inline function
}

2. Pass Object As An Argument
/*C++ PROGRAM TO PASS OBJECT AS AN ARGUMEMT. The program Adds the two heights given in feet and inches. */
#include< iostream.h>
#include< conio.h> class height
{ int feet,inches; public: void gethtint f,int i
{ feet=f; inches=i;
} void putheight
{ cout< < " nHeight is:"< < feet< < "feet t"< < inches< < "inches"< < endl;
} void sumheight a,height b)
{ height n; n.feet = a.feet + b.feet; n.inches = a.inches + b.inches; ifn.inches ==12)
{ n.feet++; n.inches = n.inches -12;
} cout< < endl< < "Height is "< < n.feet< < " feet and "< < n.inches< < endl;
}}; void main(
{height h,d,a; clrscr; h.getht6,5; a.getht2,7); h.putheight; a.putheight; d.sumh,a; getch(;
}
/OUTPUT*
Height is:6feet 5inches
Height is:2feet 7inches
Height is 9 feet and 0
.................................................................
2. 4.Marks Solved Problems: 

Q 1 Define a class TAXPAYER in C++ with following description: Private members: -  Name of type string
-  PanNo of type string
-  Taxabincm (Taxable income of type float
-  TotTax of type double
-  A function CompTax ) to calculate tax according to the following slab:
Taxable Income
Tax%
Up to 160000
0
>160000 and <=300000
5
>300000 and <=500000
1. >500000
1. Public members: -  A parameterized constructor to initialize all the members
-  A function INTAX ) to enter data for the tax payer and call function CompTax ) to assign TotTax.
-  A function OUTAX ) to allow user to view the content of all the data members.
Ans. class TAXPAYER
{ char Name[30],PanNo[30]; float Taxabincm; double TotTax; void CompTax
{ ifTaxabincm >500000
TotTax= Taxabincm*0.15; else ifTaxabincm>300000)
TotTax= Taxabincm*0.1;
Else ifTaxabincm>160000)
TotTax= Taxabincm*0.05; else
TotTax=0.0; } public:
TAXPAYERchar nm[], char pan[], float tax, double tax //parameterized constructor
{ strcpyName,nm; strcpyPanNo,pan;
Taxabincm=tax;
TotTax=ttax; } void INTAX
{ gets(Name; cin>>PanNo>>Taxabincm;
CompTax; } void OUTAX
{ cout<<Name<<’ n’<<PanNo<<’ n’<<Taxabincm<<’ n’<<TotTax<<endl; }
};
2. 

Q 2 : Define a class HOTEL in C++ with the following description:
Private Members
-  Rno
//Data Member to store Room No
-  Name
//Data Member to store customer Name
-  Tariff
//Data Member to store per day charge
-  NOD
//Data Member to store Number of days
-  CALC
//A function to calculate and return amount as NOD*Tariff and if the value of NOD*Tariff is more than 10000 then as
1.05*NOD*Tariff
Public Members:
? Checkin( )
//A function to enter the content RNo,Name, Tariff and
NOD
? Checkout
//A function to display Rno, Name, Tariff, NOD and Amount (Amount to be displayed by calling function CALC )
Solution: #include<iostream.h> class HOTEL
{ unsigned int Rno; char Name[25]; unsigned int Tariff; unsigned int NOD; int CALC
{ int x; x=NOD*Tariff; if x>10000) return(1.05*NOD*Tariff; else return(NOD*Tariff;
} public: void Checkin(
{cin>>Rno>>Name>>Tariff>>NOD;} void Checkout
{cout<<Rno<<Name<<Tariff<<NOD<<CALC;}
};

Q 3 Define a class Applicant in C++ with following description:
Private Members
-  A data member ANo ( Admission Number of type long
-  A data member Name of type string
-  A data member Agg(Aggregate Marks) of type float
-  A data member Grade of type char
-  A member function GradeMe ) to find the Grade as per the Aggregate Marks obtained by a student. Equivalent Aggregate marks range and the respective Grades are shown as follows
Aggregate Marks
Grade
> = 80
A
Less than 80 and > = 65
B
Less than 65 and > = 50
C
Less than 50
D
2. Public Members
-  A function Enter ) to allow user to enter values for ANo, Name, Agg & call function
GradeMe to find the Grade
-  A function Result ( ) to allow user to view the content of all the data members.
Ans:class Applicant
{long ANo; char Name[25]; float Agg; char Grade; void GradeMe )
{ if (Agg > = 80
Grade = ‘A’; else if (Agg >= 65 && Agg < 80
Grade = ‘B’; else if (Agg >= 50 && Agg < 65
Grade = ‘C; else
Grade = ‘D’;
} public: void Enter ( )
{ cout <<” n Enter Admission No.
“; cin>>ANo; cout <<” n Enter Name of the Applicant “; cin.getlineName,25); cout <<” n Enter Aggregate Marks obtained by the Candidate :“; cin>>Agg;
GradeMe );
} void Result )
{ cout <<” n Admission No. “<<ANo; cout <<” n Name of the Applicant “;<<Name; cout<<” n Aggregate Marks obtained by the Candidate.
“ << Agg; cout<< n Grade Obtained is “ << Grade ;
}
};

Q 4 Define a class ITEM in C++ with following description:
Private members:
-  Icode of type integer (Item Code
-  Item of type string (Item Name
-  Price of type Float (Price of each item
-  Qty of type integer (Quantity in stock
-  Discount of type float (Discount percentage on the item
-  A find function finddisc ) to calculate discount as per the following rule:
If Qty <=50 discount is 0%
If 50 < Qty <=100 discount is 5%
If Qty>100 discount is 10%
Public members: A function Buy( ) to allow user to enter values for Icode, Item,Price, Qty and call function
Finddisc ( ) to calculate the discount.
A function showall ( ) to allow user to view the content of all the data members.
2. Ans : class ITEM
{int Icode,Qty; char item[20]; float price,discount; void finddisc; public: void buy; void showall;
}; void stock::finddisc
{If (qty<=50)
Discount=0;
Else if (qty> 50 && qty <=100)
Discount=0.05*price;
Else if (qty>100)
Discount=0.10*price;
} void stock::buy
{cout<<"Item Code :";cin>>Icode; cout<<"Name :";gets(Item; cout<<"Price :";cin>>Price; cout<<"Quantity :";cin>>Qty; finddisc;
} void TEST::DISPTEST
{cout<<"Item Code :";cout<<Icode; cout<<"Name :";cout<<Item; cout<<"Price :";cout<<Price; cout<<"Quantity :";cout<<Qty; cout<<"Discount :";cout<<discount;
}
4.marks Practice Problems: 

Q 1 Define a class employee with the following specifications: Private members of class employee
-  empno integer
-  ename
2. characters
-  basic, hra, da float
-  netpay float
-  calculate A function to calculate basic + hra + da with float return type

Public member function of class employee
-  havedata function to accept values fo r empno, sname, basic, hra, da and invoke calculate to calculate netpay.
-  dispdata function to display all the data members on the screen.

Q2 Define a class Student with the following specifications: Private members: -  roll_no integer
-  name
2. characters
-  class
8.characters
-  marks[5] integer
-  percentage float
4
2. - 
Calculate a function that calculates overall percentage of marks and return the percentage of marks. public members: -  Readmarks( a function that reads marks and invoke the Calculat e function.
-  Displaymarks( a function that prints the marks.

Q3 : Define a class report with the following specification: 4
Private members: -  adno
4.digit admission number
-  name
2. characters
-  marks an array of 5 floating point values
-  average average marks obtained
-  getavg to compute the average obtained in five subjects
Public members: -  readinfo( function to accept values for adno, name, marks, and invoke the function getavg.
-  displayinfo( function to display all data members on the screen you should give function definitions.

Q4 Declare a class myfolder with the following specification: 4
Private members of the class
-  Filenames – an array of strings of size[10][25] to represent all the names of files inside myfolder
-  Availspace – long to represent total number of bytes available in myfolder
-  Usedspace – long to represent total number of bytes used in myfolder public members of the class- Newfileentry – A function to accept values of Filenames, Availspace and Usedspace fromuser
Retavailspace – A Fucntion that returns the value of total Kilobytes available
1.Kilobytes = 1024 bytes)
Showfiles( – a function that displays the names of all the files in myfolder

2.Marks Practice Problems
1. What is relation between class and object?
2. What are inline functions? Give example
3. Difference between private & public access specifiers.
4. How class implements data-hiding & encapsulation?
5. What is the difference between structure and a class ?
6. How is inline function different from a normal function ?

2. CONSTRUCTORS AND DESTRUCTORS
CONSTRUCTORS: A member function with the same as its class is called Constructor and it is used to initialize the object of that class with a legal initial value.
Example : class Student
{ int rollno; float marks; public: student )
//Constructor
{ rollno=0; marks=0.0;
}
//other public members
};

TYPES OF CONSRUCTORS:
1. Default Constructor:
A constructor that accepts no parameter is called the Default Constructor. If you don't declare a constructor or a destructor, the compiler makes one for you. The default constructor and destructor take no arguments and do nothing.
2. Parameterized Constructors:
A constructor that accepts parameters for its invocation is known as parameterized Constructors , also called as Regular Constructors.

DESTRUCTORS:

-  A destructor is also a member function whose name is the same as the class name but is preceded by tilde“~”.It is automatically by the compiler when an object is destroyed.
Destructors are usually used to deallocate memory and do other cleanup for a class object and its class members when the object is destroyed.

-  A destructor is called for a class object when that object passes out of scope or is explicitly deleted.
Example : class TEST

{ int Regno,Max,Min,Score;
Public:
TEST )
// Default Constructor
{
}
TEST (int Pregno,int Pscore
// Parameterized Constructor
{
Regno = Pregno ;Max=100;Max=100;Min=40;Score=Pscore;
}
~ TEST ( )
// Destructor
{ Cout<<”TEST Over”<<endl;}
};

The following points apply to constructors and destructors:
-  Constructors and destructors do not have return type, not even void nor can they return values.
-  References and pointers cannot be used on constructors and destructors because their addresses cannot be taken.

2. Constructors cannot be declared with the keyword virtual.
Constructors and destructors cannot be declared static, const, or volatile.
Unions cannot contain class objects that have constructors or destructors.
The compiler automatically calls constructors when defining class objects and calls destructors when class objects go out of scope.
Derived classes do not inherit constructors or destructors from their base classes, but they do call the constructor and destructor of base classes.
The default destructor calls the destructors of the base class and members of the derived class.
The destructors of base classes and members are called in the reverse order of the completion of their constructor:
The destructor for a class object is called before destructors for members and bases are called.

Copy Constructor- A copy constructor is a special constructor in the C++ programming language used to create a new object as a copy of an existing object.
A copy constructor is a constructor of the form classnameclassname &. The compiler will use the copy constructors whenever you initialize an instance using values of another instance of the same type.
Copying of objects is achieved by the use of a copy constructor and a assignment operator.

Example : class Sample{ int i, j;} public:
Sampleint a, int b)
// constructor
{ i=a;j=b;}
Sample (Sample & s
//copy constructor
{ j=s.j ; i=s.j;
Cout <<” n Copy constructor working n”;
} void print (void)
{cout <<i<< j<< ” n”;}
:
};

Note : The argument to a copy constructor is passed by reference, the reason being that when an argument is passed by value, a copy of it is constructed. But the copy constructor is creating a copy of the object for itself, thus ,it calls itself. Again the called copy constructor requires another copy so again it is called.in fact it calls itself again and again until the compiler runs out of the memory .so, in the copy constructor, the argument must be passed by reference.
The following cases may result in a call to a copy constructor:When an object is passed by value to a function:
The pass by value method requires a copy of the passed argument to be created for the function to operate upon .Thus to create the copy of the passed object, copy constructor is invoked
If a function with the following prototype : void cpyfuncSample );
// Sample is a class then for the following function call cpyfuncobj1);
// obj1 is an object of Sample type the copy constructor would be invoked to create a copy of the obj1 object for use by cpyfunc.

2. When a function returns an object: When an object is returned by a function the copy constructor is invoked
Sample cpyfunc; // Sample is a class and it is return type of cpyfunc
If func cpyfunc is called by the following statement obj2 = cpyfunc;
Then the copy constructor would be invoked to create a copy of the value returned by cpyfunc and its value would be assigned to obj2. The copy constructor creates a temporary object to hold the return value of a function returning an object.
........................................................................................................
1.& 2 Marks Solved Problems: 

Q1 :- Answer the questions after going through the following class. class Exam
{char Subject[20] ; int Marks ; public: Exam
// Function 1
{strcpySubject, “Computer” ) ; Marks = 0 ;}
Examchar P[ ]
// Function 2
{strcpySubject, P ;
Marks=0 ;
}
Examint M)
// Function 3
{strcpySubject, “Computer” ; Marks = M ;}
Examchar P[ ], int M)
// Function 4
{strcpySubject, P ; Marks = M ;}
}; a
Which feature of the Object Oriented Programming is demonstrated using Function 1,
Function2, Function 3 and Function 4 in the above class Exam?
Ans:- Function Overloading Constructor overloading b)
Write statements in C++ that would execute Function 3 and Function 4 of class Exam.
Ans:- Exam a10); and Exam b(“Comp”, 10);

Q2 Consider the following declaration : class welcome
{public: welcome (int x, char ch;
// constructor with parameter welcome;
// constructor without parameter void compute; private: int x; char ch;
}; which of the following are valid statements welcome obj (33, ‘a9’; welcome obj1(50, ‘9’; welcome obj3(; obj1= welcome (45, ‘T’; obj3= welcome;
2. Ans.
Valid and invalid statements are welcome obj (33, ‘a9’; welcome obj1(50, ‘9’; welcome obj3(; obj1= welcome (45, ‘T’; obj3= welcome; valid valid invalid valid invalid

2.Marks Practice Problems

Q1 What do you understand by constructor and destructor functions used in classes ? How are these functions different from other member functions ?

Q2 What do you understand by default constructor and copy constructor functions used in classes? How are these functions different from normal constructors ?

Q3 Given the following C++ code, answer the questions (i & (ii.
2.class TestMeOut
{ public: ~TestMeOut // Function 1
{ cout << "Leaving the examination hall " << endl; }
TestMeOut // Function 2
{ cout << "Appearing for examination " << endl; } void MyWork // Function 3
{ cout << "Attempting Questions " << endl; }
}; i In Object Oriented Programming, what is Function 1 referre d as and when does it get invoked
/ called ? ii In Object Oriented Programming, what is Function 2 referred as and when does it get invoked
/ called ?

3. INHERITANCE- Inheritance is the process by which new classes called derived classes are created from existing classes called base classes.
The derived classes have all the features of the base class and the programmer can choose to add new features specific to the newly created derived class.
The idea of inheritance implements the is a relationship. For example, mammal IS-A animal, dog IS-A mammal hence dog IS-A animal as well and so on.

Features or Advantages of Inheritance:
Reusability of Code
Saves Time and Effort
Faster development, easier maintenance and easy to extend
Capable of expressing the inheritance relationship and its transitive nature which ensures closeness with real world problems .
Base & Derived Classes:
A class can be derived from more than one classes, which means it can inherit data and functions from multiple base classes. A class derivation list names one or more base classes and has the form: class derived-class: access-specifier base-class
Where access is one of public, protected, or private.
For example, if the base class is MyClass and the derived class is sample it is specified as: class sample: public MyClass
The above makes sample have access to both public and protected variables of base class
MyClass.
EXAMPLE OF SINGLE INHERITANCE
Consider a base class Shape and its derived class Rectangle as follows:
// Base class class Shape
{ public: void setWidth(int w
{ width = w;
} void setHeightint h)
{ height = h;
} protected: int width; int height;
};
3. // Derived class class Rectangle: public Shape
{ public: int getArea
{ return (width * height;
}
}; int main(void)
{
Rectangle Rect;
Rect.setWidth(5);
Rect.setHeight7);
// Print the area of the object. cout << "Total area: " << Rect.getArea << endl; return 0;
}

When the above code is compiled and executed, it produces following result:
Total area: 35
Access Control and Inheritance:
A derived class can access all the non-private members of its base class. Thus base-class members that should not be accessible to the member functions of derived classes should be declared private in the base class.We can summarize the different access types according to who can access them in the following way:
Access public protected private
Same class yes yes yes
Derived classes yes yes no
Outside classes yes no no
A derived class inherits all base class methods with the following exceptions:- Constructors, destructors and copy constructors of the base class.
Overloaded operators of the base class.
The friend functions of the base class.
When deriving a class from a base class, the base class may be inherited through public, protected or private inheritance. We hardly use protected or private inheritance but public inheritance is commonly used. While using different type of inheritance, following rules are applied:
3. 1. Public Inheritance: When deriving a class from a public base class, public members of the base class become public members of the derived class and protected members of the base class become protected members of the derived class. A base class's private members are never accessible directly from a derived class, but can be accessed through calls to the public and protected members of the base class.
2. Protected Inheritance: When deriving from a protected base class, public and protected members of the base class become protected members of the derived class.
3. Private Inheritance: When deriving from a private base class, public and protected members of the base class become private members of the derived Class.

TYPES OF INHERITANCE
1. Single class Inheritance:Single inheritance is the one where you have a single base class and a single derived class.
Class A it is a Base class (super
Class B it is a sub class (derived)

2. Multilevel Inheritance:In Multi level inheritance, a subclass inherits from a class that itself inherits from another class.
Class A it is a Base class (super of B
Class B it is a sub class (derived) of A and base class of class C
Class C derived classsub) of c lass B

3. Multiple Inheritance:
-  In Multiple inheritances, a derived class inherits from multiple base classes. It has properties of both the base classes.
Class A
Class B
Class C
Base class
Derived class
3. 4. Hierarchical Inheritance:
-  In hierarchial Inheritance, it's like an inverted tree. So multiple classes inherit from a single base class.
Base Class
Class A
Class B
Class C
Sub Class( derived
Class D

5. Hybrid Inheritance:
-  It combines two or more forms of inheritance .In this type of inheritance, we can have mixture of number of inheritances but this can generate an error of using same name function from no of classes, which will bother the compiler to how to use the functions.
-  Therefore, it will generate errors in the program. This has known as ambiguity or duplicity.
-  Ambiguity problem can be solved by using virtual base classes
Class A
Class B
Class C
Class D
...........................................................................................
4.marks Solved Problems: 

Q1. Consider the following declarations and answer the questions given below : class WORLD
{ int H; protected : int S; public : void INPUTint; void OUTPUT;
}; class COUNTRY : private WORLD
{ int T; protected : int U; public : void INDATA int, int void OUTDATA;
}; class STATE : public COUNTRY
{ int M; public : void DISPLAY (void;};
3. i Name the base class and der ived class of the class COUNTRY. ii Name the data members) that can be accessed from function DISPLAY. iii Name the member function(s), which can be accessed from the objects of class STATE. iv Is the member function OUTPUT accessible by the obj ects of the class COUNTRY ?
Ans (i Base class : WORLD
Derived class : STATE ii M. iii DISPLAY, INDATA and OUTDATA iv No

Q2. Consider the following declarations and answer the questions given below : class living_being { char name[20]; protected: int jaws; public: void inputdata(char, int; void outputdata(;
} class animal : protected living_being { int tail; protected: int legs; public: void readdata(int, int; void writedata(;
}; class cow : private animal { char horn_size; public: void fetchdata(char; void displaydata(;
}; i Name the base class and derived class of the class animal. ii Name the data members) that can be accessed from function displaydata. iii Name the data members) that can be accessed by an object of cow class. iv Is the member function outputdata accessible to the objects of animal class.
Ans (i Base class : living_being
Derived class : cow ii horn_size, legs, jaws iii fetchdata and displaydata iv No

Q3. Consider the following and answer the questions given below : class MNC
{ char Cname[25]; // Company name protected : char Hoffice[25]; // Head office public: MNC ); char Country[25]; void EnterDate ); void DisplayData( );
};
3. class Branch : public MNC
{ long NOE; // Number of employees char Ctry[25]; // Country protected: void Association ); public: Branch ); void Add ); void Show );
}; class Outlet : public Branch
{ char State[25]; public: Outlet; void Enter; void Output;}; i Which class’s constructor will be called first at the t ime of declaration of an object of class Outlet? ii How many bytes an object belonging to class Outlet require ? iii Name the member functions), which are accessed from the objects of class Outlet. iv Name the data members), which are accessib le from the objects) of class Branch.
Ans (i class MNC ii 129 iii void Enter, void Output, void Add(, void Show, void EnterData, void DisplayData. iv char country[25]

Q4 Consider the following and answer the questions given below : class CEO { double Turnover; protected : int Noofcomp; public: CEO ); void INPUT ); void OUTPUT );
}; class Director : public CEO { int Noofemp; public: Director ); void INDATA; void OUTDATA ); protected: float Funda;
}; class Manager : public Director { float Expense; public: Manager; void DISPLAYvoid;
};
3. i Which constructor will be called first at the time of declaration of an object of class
Manager? ii How many bytes will an object belonging to class Manager require ? iii Name the memb er functions), which are directly accessible from the objects of class
Manager. iv Is the member function OUTPUT accessible by the objects of the class Director ?
Ans (i CEO ii 16 iii DISPLAY, INDATA, OUTDATA, INPUT, OUTPUT iv Ye s

4.marks Practice Problems:

Q1 :- Consider the following declarations and answer the questions given below: class vehicle
{int wheels; protected: int passenger; public: void inputdata( int, int; void outputdata(;}; class heavyvehicle: protected vehicle
{int dieselpetrol; protected: int load; public: void readdata( int, int; void writedata(;}; class bus:private heavyvehicle
{char marks[20]; public: void fetchdata(char; void displaydata(;}; i
Name the class and derived class of the class heavyvehicle. ii
Name the data members that can be accessed from function displaydata( iii
Name the data members that can be accessed by an object of bus class iv
Is the member function outputdata( accessible to the objects of heavyvehicle class.

Q2:- Consider the following declarations and answer the questions given below: class book
{ char title[20]; char author[20]; int noof pages; public: void read; void show;}; class textbook: private textbook
{int noofchapters, noofassignments; protected: int standard; void readtextbook; void showtextbook;}; class physicsbook: public textbook
{char topic[20];
3. public: void readphysicsbook; void showphysicsbook;} i ii iii iv
Name the members, which can be accessed from the member functions of class physicsbook.
Name the members, which can be accessed by an object of Class textbook.
Name the members, which can be accessed by an object of Class physicsbook.
What will be the size of an object (in bytes) of class physicsbook.

Q3 : Answer the questions (i to (iv) based on the following: class CUSTOMER
{ int Cust_no; char Cust_Name[20]; protected: void Register; public:
CUSTOMER ); void Status( );}; class SALESMAN
{ int Salesman_no; char Salesman_Name[20]; protected: float Salary; public:
SALESMAN ); void Enter ); void Show );}; class SHOP : private CUSTOMER, public SALESMAN
{ char Voucher_No[10]; char Sales_Date[8; public: SHOP ); void Sales_Entry( ); void Sales_Detail );};

i Write the names of data members, which are accessible from object belonging to class CUSTOMER.
ii Write the names of all the member functions which are accessible from object belonging to class SALESMAN.
iii Write the names of all the members which are accessible from member functions of class SHOP.
iv How many bytes will be required by an object belonging to class SHOP?

2 marks Practice Problems:
What is access specifier ? What is its role ?
What are the types of inheritance ?
What is the significance of inheritance ?
What is the difference between private and public visibility modes?