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

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{| border=1
 
{| border=1
 
| '''Time'''
 
| '''Time'''
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|-
 
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| 00:01
 
| 00:01
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|  Welcome to the spoken tutorial on '''abstract class''' and '''pure virtual function''' in '''C++.'''
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|  Welcome to the '''spoken-tutorial''' on '''abstract class''' and '''pure virtual function''' in '''C++.'''
  
 
|-
 
|-
 
| 00:08  
 
| 00:08  
−
|In this tutorial we will learn,
+
|In this tutorial, we will learn:
  
 
|-
 
|-
 
| 00:10
 
| 00:10
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|*Abstract Classes
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| Abstract Classes, Pure virtual function.
−
 
+
−
|-
+
−
| 00:11
+
−
|*Pure virtual function
+
  
 
|-
 
|-
 
| 00:13
 
| 00:13
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|*We will do this through an example.
+
|We will do this through an example.
  
 
|-
 
|-
 
| 00:16   
 
| 00:16   
−
|  To record this tutorial, I am using
+
|  To record this tutorial, I am using:
  
 
|-
 
|-
 
| 00:19
 
| 00:19
−
|*'''Ubuntu OS '''version 11.10
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|'''Ubuntu OS '''version '''11.10'''
  
 
|-
 
|-
 
| 00:23
 
| 00:23
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|*'''g++ compiler '''v. 4.6.1
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|'''g++ compiler '''version '''4.6.1'''
  
 
|-
 
|-
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|-
 
|-
 
| 00:39
 
| 00:39
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|We cannot create an instance of '''abstract class.'''
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|We cannot create an '''instance''' of '''abstract class.'''
  
 
|-
 
|-
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|-
 
|-
 
| 01:04
 
| 01:04
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|Otherwise the '''compiler''' will give an error.
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|Otherwise the '''compiler''' will give an '''error'''.
  
 
|-
 
|-
 
| 01:07
 
| 01:07
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|It is upto a '''derived class''' to implement the '''function'''.
+
|It is up to a '''derived class''' to implement the '''function'''.
  
 
|-
 
|-
 
| 01:11
 
| 01:11
−
|  Let us look at an example
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|  Let us look at an example.
  
 
|-
 
|-
 
| 01:13
 
| 01:13
−
|I have already typed the code on the editor.
+
|I have already typed the '''code''' on the '''editor'''.
  
 
|-
 
|-
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|-
 
|-
 
| 01:18
 
| 01:18
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|Note that our filename is '''abstract.cpp'''
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|Note that our file name is '''abstract.cpp'''.
  
 
|-
 
|-
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|-
 
|-
 
| 01:30
 
| 01:30
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|  This is our header file as '''iostream.'''
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|  This is our '''header file''' as '''iostream.'''
  
 
|-
 
|-
 
| 01:33
 
| 01:33
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|  Here we are using '''std namespace.'''
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|  Here we are using the '''std namespace.'''
  
 
|-
 
|-
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|-
 
|-
 
| 01:44
 
| 01:44
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|  In this we have declared a''' virtual function''' named '''"numbers".'''
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|  In this, we have declared a''' virtual function''' named '''numbers().'''
  
 
|-
 
|-
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|-
 
|-
 
| 01:55
 
| 01:55
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|And two '''integer variables''' as '''a''' and '''b'''.
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|And two '''integer variables''' as 'a' and 'b'.
  
 
|-
 
|-
 
| 01:59
 
| 01:59
−
| Here we access the '''input function.'''
+
| Here, we access the '''input function.'''
  
 
|-
 
|-
 
| 02:01
 
| 02:01
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|In this we accept the numbers '''a''' and '''b'''.
+
|In this, we accept the numbers 'a' and 'b'.
  
 
|-
 
|-
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|-
 
|-
 
| 02:14
 
| 02:14
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|  Here we override the '''function "numbers"'''.
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|  Here we '''override''' the function '''numbers()'''.
  
 
|-
 
|-
 
| 02:18
 
| 02:18
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|In this we perform addition of two numbers '''a '''and''' b.'''
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|In this, we perform addition of two numbers 'a'and 'b'  
  
 
|-
 
|-
 
| 02:21
 
| 02:21
−
|And store the result in '''integer variable "sum".'''
+
|and store the result in '''integer variable "sum".'''
  
 
|-
 
|-
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|-
 
|-
 
|  02:35
 
|  02:35
−
| In this, again, we override the '''function "numbers"'''.
+
| In this, again we override the function '''numbers()'''.
  
 
|-
 
|-
 
| 02:39
 
| 02:39
−
|And here we calculate the difference of two numbers '''a''' and '''b'''.
+
|And here we calculate the difference of two numbers 'a' and 'b'.
  
 
|-
 
|-
 
| 02:43
 
| 02:43
−
|Then we print the difference.
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|Then we '''print''' the difference.
  
 
|-
 
|-
 
| 02:45
 
| 02:45
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|  This is our '''main function.'''
+
|  This is our '''main()''' function.
  
 
|-
 
|-
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|-
 
|-
 
| 02:53
 
| 02:53
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|Then we call both the '''functions "input" '''and''' "numbers" '''using the '''object obj1.'''
+
|Then we call both the functions '''input() '''and''' numbers() '''using the '''object obj1.'''
  
 
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|-
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|-
 
|-
 
| 03:04
 
| 03:04
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|Again, we call the two "functions''' using the '''object obj2.'''
+
|Again, we call the two '''functions''' using the '''object obj2.'''
  
 
|-
 
|-
 
| 03:08
 
| 03:08
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|  And this is our '''return statement'''.
+
|  And this is our''' 'return' statement'''.
  
 
|-
 
|-
 
| 03:10
 
| 03:10
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|  Now let us execute the program.
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|  Now let us '''execute''' the program.
  
 
|-
 
|-
 
| 03:13
 
| 03:13
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|  Open the '''terminal window''' by pressing '''Ctrl, Alt and T '''keys simultaneously on your keyboard.
+
|  Open the '''terminal window''' by pressing '''Ctrl, Alt''' and '''T '''keys simultaneously on your keyboard.
  
 
|-
 
|-
 
| 03:21
 
| 03:21
 
|  To compile, type:  
 
|  To compile, type:  
−
'''g++ space abstract dot cpp space hyphen o space abs'''
+
'''g++ space abstract dot cpp space hyphen o space abs'''
  
 
|-
 
|-
 
| 03:31
 
| 03:31
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|'''Press Enter'''
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|press '''Enter'''.Type: '''dot slash abs'''
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+
−
|-
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| 03:32
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−
|Type:
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−
'''dot slash abs'''
+
  
 
|-
 
|-
 
| 03:34
 
| 03:34
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|'''Press Enter'''
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|press '''Enter'''.
  
 
|-
 
|-
 
| 03:36
 
| 03:36
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|  It is displayed as  '''Enter the numbers'''  
+
|  It is displayed as  '''Enter the numbers'''.
  
 
|-
 
|-
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|-
 
|-
 
| 03:42
 
| 03:42
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|The output is displayed as '''Sum is 13'''
+
|The '''output''' is displayed as '''Sum is 13'''.
  
 
|-
 
|-
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|-
 
| 03:52
 
| 03:52
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|The output is displayed as '''Diff is 5'''
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|The '''output''' is displayed as '''diff is 5'''.
  
 
|-
 
|-
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| 03:56
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|03:56
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| This brings us to the end of this tutorial.
+
|This brings us to the end of this tutorial.
  
 
|-
 
|-
 
| 03:59
 
| 03:59
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|Come back to our slides.
+
|Come back to our '''slides'''.
  
 
|-
 
|-
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| 04:03
 
| 04:03
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|In this tutorial we learnt,
+
|In this tutorial, we learnt:'''Abstract class''' e.g. '''class abstractinterface'''.
−
 
+
−
|-
+
−
| 04:04
+
−
|'''Abstract class''' '''eg. class abstractinterface'''
+
  
 
|-
 
|-
 
| 04:09
 
| 04:09
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|'''Pure virtual function''' '''eg. virtual void numbers()=0;'''
+
|'''Pure virtual function''' e.g. '''virtual void numbers()=0;'''
  
 
|-
 
|-
 
| 04:14
 
| 04:14
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|  As an assignment  
+
|  As an assignment- Create an '''abstract class''' '''student.'''
−
*Create an abstract class '''student.'''
+
  
 
|-
 
|-
 
| 04:17
 
| 04:17
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|*Create a pure virtual function as '''Info'''  
+
|Create a '''pure virtual function''' as '''Info'''.
  
 
|-
 
|-
 
| 04:20
 
| 04:20
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|*Accept the '''name''' and '''roll no''' of the student in the function.
+
|Accept the '''name''' and '''roll no''' of the student in the function.
  
 
|-
 
|-
 
| 04:25
 
| 04:25
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|*Create two derived class '''marks''' and '''sports'''.
+
|Create two '''derived class'''es '''marks''' and '''sports'''.
  
 
|-
 
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| 04:29
 
| 04:29
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|*In marks, accept marks of three subjects.
+
|In marks, accept marks of three subjects.
  
 
|-
 
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| 04:32
 
| 04:32
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|*In sports, enter marks scored in '''sports.'''
+
|In sports, enter marks scored in '''sports.'''
  
 
|-
 
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| 04:35
 
| 04:35
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|*Calculate the '''total marks.'''
+
|Calculate the '''total marks.'''
  
 
|-
 
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| 04:38
 
| 04:38
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|*Then create another derived class as '''result.'''
+
|Then create another '''derived class''' as '''result.'''
  
 
|-
 
|-
 
| 04:41
 
| 04:41
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|*In this, display the''' name, roll-no, total marks''' of the student.  
+
|In this, display the''' name, roll-no''' and '''total marks''' of the student.  
  
 
|-
 
|-
 
| 04:47
 
| 04:47
−
|  Watch the video available at the link shown below
+
|  Watch the video available at the link shown below.
  
 
|-
 
|-
 
| 04:50
 
| 04:50
−
|It summarizes the Spoken Tutorial project  
+
|It summarizes the Spoken-Tutorial project.
  
 
|-
 
|-
 
| 04:53
 
| 04:53
−
|If you do not have good bandwidth, you can download and watch it
+
|If you do not have good bandwidth, you can download and watch it.
  
 
|-
 
|-
 
| 04:58
 
| 04:58
−
| The Spoken Tutorial Project Team Conducts workshops using spoken tutorials  
+
|The Spoken Tutorial Project team: Conducts workshops using spoken tutorials.
  
 
|-
 
|-
 
| 05:03
 
| 05:03
−
|Gives certificates to those who pass an online test  
+
|Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
| 05:07
 
| 05:07
−
|For more details, please write to, contact@spoken-tutorial.org
+
|For more details, please write to: contact@spoken-tutorial.org
  
 
|-
 
|-
 
| 05:14  
 
| 05:14  
−
| Spoken Tutorial Project is a part of the Talk to a Teacher project
+
|Spoken-Tutorial Project is a part of the "Talk to a Teacher" project.
  
 
|-
 
|-
 
| 05:18
 
| 05:18
−
|It is supported by the National Mission on Education through ICT, MHRD, Government of India
+
|It is supported by the National Mission on Education through ICT, MHRD, Government of India.
  
 
|-
 
|-
 
| 05:25
 
| 05:25
−
|More information on this Mission is available at the link shown below: [http://spoken-tutorial.org/NMEICT-Intro http://spoken-tutorial.org\NMEICT-Intro]
+
|More information on this mission is available at the link shown below: http://spoken-tutorial.org/NMEICT-Intro
  
 
|-
 
|-
 
| 05:30
 
| 05:30
−
| This is Ashwini Patil from IIT Bombay signing off
+
|This is Ashwini Patil from IIT Bombay, signing off.Thank You for watching.  
−
 
+
−
Thank You for watching.  
+
  
 
|}
 
|}

Latest revision as of 15:04, 23 March 2017

Time Narration
00:01 Welcome to the spoken-tutorial on abstract class and pure virtual function in C++.
00:08 In this tutorial, we will learn:
00:10 Abstract Classes, Pure virtual function.
00:13 We will do this through an example.
00:16 To record this tutorial, I am using:
00:19 Ubuntu OS version 11.10
00:23 g++ compiler version 4.6.1
00:27 Let us start with an introduction to abstract class.
00:31 Abstract class is always a base class.
00:35 It contains at least one pure virtual function.
00:39 We cannot create an instance of abstract class.
00:43 Let us see pure virtual function.
00:45 A pure virtual function is a function with no body.
00:49 It is not defined in the base class.
00:52 It is declared as:
00:54 virtual void virtualfunname()=0;
01:00 A derived class must override the function.
01:04 Otherwise the compiler will give an error.
01:07 It is up to a derived class to implement the function.
01:11 Let us look at an example.
01:13 I have already typed the code on the editor.
01:16 I will open it.
01:18 Note that our file name is abstract.cpp.
01:22 This example involves addition and subtraction of two numbers.
01:28 Let us go through the code.
01:30 This is our header file as iostream.
01:33 Here we are using the std namespace.
01:36 This is declaration for a class named abstractinterface.
01:41 Then we have public specifier.
01:44 In this, we have declared a virtual function named numbers().
01:49 It is initialized to 0.
01:51 Then we have a non-virtual function.
01:55 And two integer variables as 'a' and 'b'.
01:59 Here, we access the input function.
02:01 In this, we accept the numbers 'a' and 'b'.
02:05 This is a derived class named add.
02:09 It inherits the properties of the base class "abstractinterface".
02:14 Here we override the function numbers().
02:18 In this, we perform addition of two numbers 'a'and 'b'
02:21 and store the result in integer variable "sum".
02:25 Then we print the result.
02:27 Here we have another derived class as sub.
02:31 This also inherits the base class "abstractinterface".
02:35 In this, again we override the function numbers().
02:39 And here we calculate the difference of two numbers 'a' and 'b'.
02:43 Then we print the difference.
02:45 This is our main() function.
02:48 Here we create an object of class "add" as obj1.
02:53 Then we call both the functions input() and numbers() using the object obj1.
02:59 Then we create another object of class "sub" as obj2.
03:04 Again, we call the two functions using the object obj2.
03:08 And this is our 'return' statement.
03:10 Now let us execute the program.
03:13 Open the terminal window by pressing Ctrl, Alt and T keys simultaneously on your keyboard.
03:21 To compile, type:

g++ space abstract dot cpp space hyphen o space abs

03:31 press Enter.Type: dot slash abs
03:34 press Enter.
03:36 It is displayed as Enter the numbers.
03:38 I will enter as 9 and 4.
03:42 The output is displayed as Sum is 13.
03:46 Again we see Enter the numbers.
03:49 I will enter as 8 and 3.
03:52 The output is displayed as diff is 5.
03:56 This brings us to the end of this tutorial.
03:59 Come back to our slides.
04:01 Let us summarize.
04:03 In this tutorial, we learnt:Abstract class e.g. class abstractinterface.
04:09 Pure virtual function e.g. virtual void numbers()=0;
04:14 As an assignment- Create an abstract class student.
04:17 Create a pure virtual function as Info.
04:20 Accept the name and roll no of the student in the function.
04:25 Create two derived classes marks and sports.
04:29 In marks, accept marks of three subjects.
04:32 In sports, enter marks scored in sports.
04:35 Calculate the total marks.
04:38 Then create another derived class as result.
04:41 In this, display the name, roll-no and total marks of the student.
04:47 Watch the video available at the link shown below.
04:50 It summarizes the Spoken-Tutorial project.
04:53 If you do not have good bandwidth, you can download and watch it.
04:58 The Spoken Tutorial Project team: Conducts workshops using spoken tutorials.
05:03 Gives certificates to those who pass an online test.
05:07 For more details, please write to: contact@spoken-tutorial.org
05:14 Spoken-Tutorial Project is a part of the "Talk to a Teacher" project.
05:18 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
05:25 More information on this mission is available at the link shown below: http://spoken-tutorial.org/NMEICT-Intro
05:30 This is Ashwini Patil from IIT Bombay, signing off.Thank You for watching.

Contributors and Content Editors

Gaurav, PoojaMoolya, Pratik kamble, Sandhya.np14

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