Advanced-C++/C2/More-On-Inheritance/English-timed

Time	Narration
00:01	Welcome to the spoken tutorial on Multiple and Hierarchical Inheritance in C++.
00:07	In this tutorial, we will learn:
00:09	* Multiple Inheritance
00:11	* Hierarchical Inheritance.
00:13	We will do this with the help of examples.
00:17	To record this tutorial, I am using:
00:20	Ubuntu OS version 11.10 and
00:24	g++ compiler version 4.6.1
00:29	In multiple inheritance, derived class inherits from more than one base class.
00:36	Now, we will see an example on multiple inheritance.
00:40	I have already typed the code on the editor.
00:42	I will open it.
00:45	Note that our file name is multiple.cpp.
00:49	In this program, we will display the name, roll no, marks and average of the student.
00:56	Let me explain the code.
00:59	This is our header file as iostream.
01:01	Here we are using the std namespace.
01:05	Then we have class student.
01:07	This is the base class.
01:09	In this, we have roll_no as integer variable and name as character variable.
01:16	These are declared as protected.
01:19	Then we have another class exam_inherit.
01:24	This is also a base class.
01:26	Hence we have two base classes here- student and exam_inherit.
01:32	In this, we have 3 variables- sub1, sub2 and sub3 as protected.
01:38	This is because protected variables can be accessed by derived class.
01:44	Now, here we have class "grade" which is the derived class.
01:50	This inherits the base classes – class "student"' and class "exam_inherit".
01:56	In this, we have avg as integer variable declared as private.
02:02	Then we have functions:
02:04	input()
02:05	display()
02:06	average()
02:07	input_exam()
02:08	and display_exam() as public functions.
02:11	In this, we have total as integer variable declared as public.
02:17	Then, we use input() function to accept the roll_no and name of the student.
02:24	In display() function, we display the roll_no and name of the student.
02:28	Here, we have function input_exam().
02:31	In this, we accept the marks of three subjects as sub1, sub2 and sub3.
02:37	Then in display_exam() function, we calculate the total of three subjects and print the total.
02:44	And in function average(), we calculate the average.
02:48	This is our main() function.
02:51	In this, we create an object of class grade which is the derived class as gd.
02:57	Then we call all the above functions.
03:01	This is our return statement.
03:03	Now, let us execute the program.
03:05	Open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard.
03:14	To compile, type: g++ space multiple dot cpp space hyphen o space mult. Press Enter.
03:24	Type: dot slash mult. Press Enter.
03:29	Here we see, Enter Roll no.:
03:32	I will enter as 3.
03:34	Enter Name:
03:36	I will enter as Pratham.
03:39	Enter marks of subject1
03:41	I will give as 67.
03:43	subject2 as 78 and.
03:46	subject3 as 84.
03:48	The output is displayed as:
03:51	Roll no is: 3
03:52	Name is: Pratham
03:53	Total is: 229
03:55	Average is: 76.
03:58	This was multiple inheritance.
04:00	Now, we will see hierarchical inheritance.
04:03	Come back to our program.
04:05	In hierarchical inheritance, multiple derived classes inherit from one base class.
04:12	Note that our 'file name' is hierarchical dot cpp.
04:16	I will explain the code now.
04:19	This is our header file as iostream.
04:22	Here we have used the std namespace.
04:25	Then, we have class student which is the base class.
04:29	In this, we have roll_no as integer variable.
04:34	Sub1, sub2, sub3 and total as integer variables.
04:40	Then name as character variable.
04:43	These are declared protected.
04:46	Here, we have another class 'show'.
04:49	This is the derived class.
04:51	It inherits the properties of class student.
04:54	In this, we have two functions: input() and display().
04:59	These are declared as public functions.
05:02	In function input(), we accept the roll_no and name of the student.
05:07	In function display(), we display the roll_no and name of the student.
05:11	Then we have another derived class as class exam.
05:15	This also inherits class student.
05:19	You can see that there are two derived classes- class exam and class show.
05:26	Both the classes inherit the class "student".
05:30	In class exam, we have two functions as input_exam() and total_marks() declared as public.
05:38	Here, we access the function input_exam().
05:41	It accepts the marks of three subjects- sub1, sub2 and sub3.
05:46	Then we have total_marks() function.
05:49	It calculates the total of three subjects and prints the total.
05:53	This is our main() function.
05:56	In this, we create objects of three classes as st, sw and em.
06:03	Then we call all the above functions using these objects. sw.input(); em.input_exam(); sw.display(); em.total_marks();
06:15	And this is our return statement.
06:17	Now, let us execute the program.
06:19	Come back to the terminal.
06:21	Let me clear the prompt.
06:24	Let us compile, type: g++ space hierarchical dot cpp space hyphen o space hier
06:36	Press Enter.
06:37	Type: dot slash hier
06:41	Press Enter.
06:43	Enter Roll no.:
06:44	I will give as 4.
06:46	Enter Name:
06:47	I will give as Ashwini.
06:50	Enter marks of subject1
06:52	I will give as 87.
06:54	subject2 as 67 and subject3 as 97.
07:00	The output is displayed as:
07:02	Roll no is: 4
07:04	Name is: Ashwini and
07:06	Total is : 251
07:07	This brings us to the end of this tutorial.
07:10	Come back to our slides.
07:13	Let us summarize.
07:14	In this tutorial, we learnt-
07:16	Multiple Inheritance and
07:18	Hierarchical Inheritance.
07:20	As an assignment:
07:21	Create a class area and perimeter.
07:25	Find the area and perimeter of rectangle.
07:29	Watch the video available at the link shown below.
07:32	It summarizes the Spoken Tutorial project.
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07:40	The Spoken Tutorial Project Team:
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07:51	contact@spoken-tutorial.org
07:56	Spoken Tutorial Project is a part of the "Talk to a Teacher" project.
08:01	It is supported by the National Mission on Education through ICT, MHRD, Government of India.
08:07	More information on this mission is available at the link shown below.
08:11	This is Ashwini Patil from IIT Bombay, signing off. Thank You for joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Sandhya.np14