Difference between revisions of "Advanced-C++/C2/Inheritance/English-timed"

| In this tutorial we will learn,

| '''Inheritance'''

 

|Types of '''inheritance'''

| To record this tutorial, I am using

|'''Ubuntu OS '''version 11.10'''

|'''g++ compiler '''v. 4.6.1'''

|  Let us start with an Introduction to Inheritance

|When one object acquires the property of another it is called as '''inheritance.'''

|It is the process of reusing the existing class without modifying them.

| Types of '''Inheritance'''

 

|-

|'''Single level inheritance'''

|'''Multilevel inheritance'''

|'''Hybrid Inheritance'''

| First let us know about the base class and the derived class.

|The base class has its own properties and functionality.

|It is also called as parent class.

|The derived class is the child class.

|Derived class inherits the properties and functionality of the base class.

|Let us see what is single level inheritance.

| In single level inheritance only one base class and one derived class is needed.

| Multiple inheritance

|In multiple inheritance derived class inherits from more than one base class.

| '''Hierarchical Inheritance'''

| In '''Hierarchical Inheritance''' multiple derived classes inherits from one base class.

| '''Multilevel inheritance'''

| In Multilevel inheritance the subclass acts as the base class for other classes.

| and '''Hybrid inheritance'''  

|  In '''hybrid inheritance''' more than one form of inheritance is combined.

|  Now let us see an example on single level inheritance.

|I have already typed the code on the editor.

|Note that our file name is  '''exam_inherit.cpp'''

 

| This is our header file as '''iostream'''

|  Here we are using the '''std namespace'''

|  Here we have class '''student.'''

|  Then we have an integer variable '''roll_no''' and '''character array name''', as private members of '''class student'''.

|  Function '''input '''and function''' display '''are the public functions of class student.

 

| Here we are using the '''input''' function to accept the roll no. and name of the student.

 

|  Then we have the '''display''' function to display the roll_no and name.

 

|  Here we have another class as '''exam_inherit.'''

|This is the derived class.

|It inherits the function and data of class student.

|  Then we have declared ''' sub1, sub2, sub3 and total.'''

|As private variables of '''class exam_inherit.'''

|  Here we have '''input_exam''' and '''display_exam as public functions.'''

|Here we close the class '''exam_inherit.'''

| Now we are using '''input_exam '''function to accept the marks of three''' '''subject.

 

|  Here, we are using '''display_exam''' function to calculate the total of three subjects.

|Then we print a total.

|  This is our '''main function.'''

|  Here we create an object of class '''exam_inherit''' as '''ex'''

| Then we call all the functions using the object '''ex'''

| And this is our return statement.

|  Let us execute the program

| Open the '''terminal''' Window by pressing '''Ctrl, Alt and T '''keys simultaneously, on your keyboard.

|  To compile, type

|'''g++ (space)exam_inherit.cpp (space)-o (space) exam'''

| Press Enter.

 

|Type

 

| 04:43

|'''./exam''' Press Enter.

|  Here it is displayed as,

 

| 04:47

|'''Enter Roll no.:'''

|'''I will give as 1'''

|'''Enter Name:'''

 

|I will enter as '''Arya'''

|I will give as '''60'''

| And '''subjec 3''' as 80'''

| The output is displayed as  

|'''Roll no is: 1'''

 

|'''Name is: Arya''' and,

|'''Total is: 210'''

|  Now we will see multilevel inheritance in the same example.

|Let's switch back to our editor.

|Note that our filename is '''multilevel.cpp'''

| Here we have declared the variable total.

|As '''public variable''' of class '''exam_inherit.'''

|This is because the private members are not accessed by the derived class.

|  Here we have another class as '''grade.'''

|Class '''grade''' is the derived class  

| And class '''exam_inherit''' is the base class for class '''grade'''.

| All the functions and data of class '''exam_inherit''' will be inherited to class '''grade'''.

| Here we have declared '''avg''' as '''private''' member of class '''grade.'''  

|And function '''average''' as '''public''' function.

|Then we close the class.

| Here we use the '''average''' function to calculate the average.

| Inside the main function we create an object of class grade as '''gd.'''

|'''input_exam'''

|'''display'''

 

|'''display_exam'''

|and the '''average function.'''

|  Now you can see that class '''grade''' is the derived class.

| And '''exam_inherit''' is the base class for class '''grade.'''

| And here class '''exam_inherit''' is the derived class.

| And class '''student''' is the base class for class '''exam_inherit.'''

| Let us execute the program.

| Come back to our terminal.

| To compile, type

 

| 07:18

|'''g++ (space) multilevel.cpp (space) -o (space) mul'''

|Press '''Enter'''

 

|Type

 

'''./mul'''

|Press '''Enter'''

|I will enter as '''2'''

|I will enter as '''Pratham'''

|I will give as '''65'''

|'''subject2 as 67''' and,

|'''subject3 as 82'''

 

| The output is displayed as:

|'''Name is: Pratham '''

 

|'''Total is: 214 ''' and,

|'''Average is: 71'''  

|Let us move back to our slides.

 

| Let us summarize

|In this tutorial, we learnt,

|'''Inheritance''' and,

 

| Types of '''inheritance.'''

|  As an assignment  

 

 

|-

| Write a program to Create a class Shape.

| Then Create two functions of the class as Area and Perimeter.

| Watch the video available at the link shown below

|It summarizes the Spoken Tutorial project  

|If you do not have good bandwidth, you can download and watch it

|  The Spoken Tutorial Project Team  

|Conducts workshops using spoken tutorials  

|Gives certificates to those who pass an online test  

|For more details, please write to,

| Spoken Tutorial Project is a part of the Talk to a Teacher project

|More information on this Mission is available at the link shown below

| This is Ashwini Patil from IIT Bombay signing off

 

Thank You for joining.