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

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(Created page with ' {| border=1 | '''Time''' | '''Narration''' |- | 00.01 | Welcome to the spoken tutorial on '''abstract class''' and '''pure virtual function''' in '''C++.''' |- | 00.08 |In…')
 
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|  Welcome to the spoken tutorial on '''abstract class''' and '''pure virtual function''' in '''C++.'''
 
|  Welcome to the spoken tutorial on '''abstract class''' and '''pure virtual function''' in '''C++.'''
  
 
|-
 
|-
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| 00.08  
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| 00:08  
 
|In this tutorial we will learn,
 
|In this tutorial we will learn,
  
 
|-
 
|-
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| 00:10
 
|*Abstract Classes
 
|*Abstract Classes
  
 
|-
 
|-
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| 00.11
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| 00:11
 
|*Pure virtual function
 
|*Pure virtual function
  
 
|-
 
|-
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| 00.13
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| 00:13
 
|*We will do this through an example.
 
|*We will do this through an example.
  
 
|-
 
|-
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| 00.16   
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| 00:16   
 
|  To record this tutorial, I am using
 
|  To record this tutorial, I am using
  
 
|-
 
|-
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| 00.19
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| 00:19
 
|*'''Ubuntu OS '''version 11.10
 
|*'''Ubuntu OS '''version 11.10
  
 
|-
 
|-
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| 00:23
 
|*'''g++ compiler '''v. 4.6.1
 
|*'''g++ compiler '''v. 4.6.1
  
 
|-
 
|-
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|  00.27
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|  00:27
 
|  Let us start with an introduction to '''abstract class.'''
 
|  Let us start with an introduction to '''abstract class.'''
  
 
|-
 
|-
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| 00.31
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| 00:31
 
|'''Abstract class '''is always a '''base class'''.
 
|'''Abstract class '''is always a '''base class'''.
  
 
|-
 
|-
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| 00.35
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| 00:35
 
|It contains at least one '''pure virtual function.'''
 
|It contains at least one '''pure virtual function.'''
  
 
|-
 
|-
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| 00.39
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| 00:39
 
|We cannot create an instance of '''abstract class.'''
 
|We cannot create an instance of '''abstract class.'''
  
 
|-
 
|-
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|  00.43
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|  00:43
 
| Let us see '''pure virtual function'''.
 
| Let us see '''pure virtual function'''.
  
 
|-
 
|-
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| 00.45
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| 00:45
 
|A '''pure virtual function''' is a function with no '''body'''.
 
|A '''pure virtual function''' is a function with no '''body'''.
  
 
|-
 
|-
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| 00.49
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| 00:49
 
|It is not defined in the '''base class'''.
 
|It is not defined in the '''base class'''.
  
 
|-
 
|-
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| 00.52
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| 00:52
 
|It is declared as:
 
|It is declared as:
  
 
|-
 
|-
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| 00.54
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| 00:54
 
|'''virtual void virtualfunname()=0;'''
 
|'''virtual void virtualfunname()=0;'''
  
 
|-
 
|-
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| 01.00
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| 01:00
 
|A '''derived class''' must override the '''function'''.
 
|A '''derived class''' must override the '''function'''.
  
 
|-
 
|-
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| 01.04
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| 01:04
 
|Otherwise the '''compiler''' will give an error.
 
|Otherwise the '''compiler''' will give an error.
  
 
|-
 
|-
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| 01.07
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| 01:07
 
|It is upto a '''derived class''' to implement the '''function'''.
 
|It is upto a '''derived class''' to implement the '''function'''.
  
 
|-
 
|-
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| 01.11
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| 01:11
 
|  Let us look at an example
 
|  Let us look at an example
  
 
|-
 
|-
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| 01.13
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| 01:13
 
|I have already typed the code on the editor.
 
|I have already typed the code on the editor.
  
 
|-
 
|-
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| 01.16
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| 01:16
 
|I will open it.
 
|I will open it.
  
 
|-
 
|-
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| 01.18
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| 01:18
 
|Note that our filename is '''abstract.cpp'''
 
|Note that our filename is '''abstract.cpp'''
  
 
|-
 
|-
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| 01.22
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| 01:22
 
|This example involves addition and subtraction of two numbers.
 
|This example involves addition and subtraction of two numbers.
  
 
|-
 
|-
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| 01.28
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| 01:28
 
|  Let us go through the code.
 
|  Let us go through the code.
  
 
|-
 
|-
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| 01:30
 
|  This is our header file as '''iostream.'''
 
|  This is our header file as '''iostream.'''
  
 
|-
 
|-
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| 01.33
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| 01:33
 
|  Here are using '''std namespace.'''
 
|  Here are using '''std namespace.'''
  
 
|-
 
|-
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| 01.36
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| 01:36
 
|  This is declaration for a '''class''' named '''abstractinterface.'''
 
|  This is declaration for a '''class''' named '''abstractinterface.'''
  
 
|-
 
|-
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| 01.41
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| 01:41
 
|  Then we have '''public specifier'''.
 
|  Then we have '''public specifier'''.
  
 
|-
 
|-
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| 01.44
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| 01:44
 
|  In this we have declared a''' virtual function''' named '''"numbers".'''
 
|  In this we have declared a''' virtual function''' named '''"numbers".'''
  
 
|-
 
|-
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| 01.49
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| 01:49
 
|It is initialized to '''0.'''
 
|It is initialized to '''0.'''
  
 
|-
 
|-
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| 01.51
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| 01:51
 
| Then we have a '''non-virtual function'''.
 
| Then we have a '''non-virtual function'''.
  
 
|-
 
|-
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| 01.55
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| 01:55
 
|And two '''integer variables''' as '''a''' and '''b'''.
 
|And two '''integer variables''' as '''a''' and '''b'''.
  
 
|-
 
|-
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| 01.59
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| 01:59
 
| Here we access the '''input function.'''
 
| Here we access the '''input function.'''
  
 
|-
 
|-
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| 02.01
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| 02:01
 
|In this we accept the numbers '''a''' and '''b'''.
 
|In this we accept the numbers '''a''' and '''b'''.
  
 
|-
 
|-
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|  02.05
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|  02:05
 
| This is a''' derived class''' named''' add.'''
 
| This is a''' derived class''' named''' add.'''
  
 
|-
 
|-
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| 02.09
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| 02:09
 
|It inherits the properties of the '''base class "abstractinterface".'''
 
|It inherits the properties of the '''base class "abstractinterface".'''
  
 
|-
 
|-
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| 02.14
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| 02:14
 
|  Here we override the '''function "numbers"'''.
 
|  Here we override the '''function "numbers"'''.
  
 
|-
 
|-
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| 02.18
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| 02:18
 
|In this we perform addition of two numbers '''a '''and''' b.'''
 
|In this we perform addition of two numbers '''a '''and''' b.'''
  
 
|-
 
|-
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| 02.21
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| 02:21
 
|And store the result in '''integer variable "sum".'''
 
|And store the result in '''integer variable "sum".'''
  
 
|-
 
|-
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| 02.25
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| 02:25
 
|Then we print the result.
 
|Then we print the result.
  
 
|-
 
|-
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| 02.27
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| 02:27
 
| Here we have another '''derived class '''as '''sub.'''
 
| Here we have another '''derived class '''as '''sub.'''
  
 
|-
 
|-
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| 02.31
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| 02:31
 
|This also inherits the''' base class "abstractinterface".'''
 
|This also inherits the''' base class "abstractinterface".'''
  
 
|-
 
|-
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|  02.35
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|  02:35
 
| In this, again, we override the '''function "numbers"'''.
 
| In this, again, we override the '''function "numbers"'''.
  
 
|-
 
|-
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| 02.39
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| 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'''.
  
 
|-
 
|-
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| 02.43
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| 02:43
 
|Then we print the difference.
 
|Then we print the difference.
  
 
|-
 
|-
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| 02.45
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| 02:45
 
|  This is our '''main function.'''
 
|  This is our '''main function.'''
  
 
|-
 
|-
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| 02.48
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| 02:48
 
|  Here we create an '''object''' of '''class "add"''' as '''obj1.'''
 
|  Here we create an '''object''' of '''class "add"''' as '''obj1.'''
  
 
|-
 
|-
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| 02.53
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| 02:53
 
|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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| 02.59
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| 02:59
 
|  Then we create another '''object''' of '''class "sub"''' as '''obj2.'''
 
|  Then we create another '''object''' of '''class "sub"''' as '''obj2.'''
  
 
|-
 
|-
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| 03.04
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| 03:04
 
|Again, we call the two "functions''' using the '''object obj2.'''
 
|Again, we call the two "functions''' using the '''object obj2.'''
  
 
|-
 
|-
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| 03.08
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| 03:08
 
|  And this is our '''return statement'''.
 
|  And this is our '''return statement'''.
  
 
|-
 
|-
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| 03.10
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| 03:10
 
|  Now let us execute the program.
 
|  Now let us execute the program.
  
 
|-
 
|-
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| 03:13
 
|  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.
  
 
|-
 
|-
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| 03.21
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| 03:21
 
|  To compile, type:  
 
|  To compile, type:  
 
  '''g++ space abstract dot cpp space hypheno space abs'''
 
  '''g++ space abstract dot cpp space hypheno space abs'''
  
 
|-
 
|-
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| 03.31
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| 03:31
 
|'''Press Enter'''
 
|'''Press Enter'''
  
 
|-
 
|-
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| 03.32
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| 03:32
 
|Type:
 
|Type:
 
  '''dot slash abs'''
 
  '''dot slash abs'''
  
 
|-
 
|-
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| 03.34
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| 03:34
 
|'''Press Enter'''
 
|'''Press Enter'''
  
 
|-
 
|-
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| 03.36
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| 03:36
 
|  It is displayed as  
 
|  It is displayed as  
 
  '''Enter the numbers'''  
 
  '''Enter the numbers'''  
  
 
|-
 
|-
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| 03.38
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| 03:38
 
|I will enter as '''9''' and '''4.'''
 
|I will enter as '''9''' and '''4.'''
  
 
|-
 
|-
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| 03.42
+
| 03:42
 
|The output is displayed as '''Sum is 13'''
 
|The output is displayed as '''Sum is 13'''
  
 
|-
 
|-
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| 03.46
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| 03:46
 
|Again we see '''Enter the numbers'''.
 
|Again we see '''Enter the numbers'''.
  
 
|-
 
|-
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| 03.49
+
| 03:49
 
|I will enter as '''8''' and '''3'''.
 
|I will enter as '''8''' and '''3'''.
  
 
|-
 
|-
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| 03.52
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| 03:52
 
|The output is displayed as '''Diff is 5'''
 
|The output is displayed as '''Diff is 5'''
  
 
|-
 
|-
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| 03.56
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| 03:56
 
| This brings us to the end of this tutorial.
 
| This brings us to the end of this tutorial.
  
 
|-
 
|-
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| 03.59
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| 03:59
 
|Come back to our slides.
 
|Come back to our slides.
  
 
|-
 
|-
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| 04.01   
+
| 04:01   
 
| Let us summarize.
 
| Let us summarize.
  
 
|-
 
|-
−
| 04.03
+
| 04:03
 
|In this tutorial we learnt,
 
|In this tutorial we learnt,
  
 
|-
 
|-
−
| 04.04
+
| 04:04
 
|'''Abstract class''' '''eg. class abstractinterface'''
 
|'''Abstract class''' '''eg. class abstractinterface'''
  
 
|-
 
|-
−
| 04.09
+
| 04:09
 
|'''Pure virtual function''' '''eg. virtual void numbers()=0;'''
 
|'''Pure virtual function''' '''eg. virtual void numbers()=0;'''
  
 
|-
 
|-
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| 04.14
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| 04:14
 
|  As an assignment  
 
|  As an assignment  
 
  *Create an abstract class '''student.'''
 
  *Create an abstract class '''student.'''
  
 
|-
 
|-
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| 04.17
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| 04:17
 
|*Create a pure virtual function as '''Info'''  
 
|*Create a pure virtual function as '''Info'''  
  
 
|-
 
|-
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| 04.20
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| 04:20
 
|*Accept the '''name''' and '''roll no''' of the student in the function.
 
|*Accept the '''name''' and '''roll no''' of the student in the function.
  
 
|-
 
|-
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| 04.25
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| 04:25
 
|*Create two derived class '''marks''' and '''sports'''.
 
|*Create two derived class '''marks''' and '''sports'''.
  
 
|-
 
|-
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| 04.29
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| 04:29
 
|*In marks, accept marks of three subjects.
 
|*In marks, accept marks of three subjects.
  
 
|-
 
|-
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| 04.32
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| 04:32
 
|*In sports, enter marks scored in '''sports.'''
 
|*In sports, enter marks scored in '''sports.'''
  
 
|-
 
|-
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| 04.35
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| 04:35
 
|*Calculate the '''total marks.'''
 
|*Calculate the '''total marks.'''
  
 
|-
 
|-
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| 04.38
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| 04:38
 
|*Then create another derived class as '''result.'''
 
|*Then create another derived class as '''result.'''
  
 
|-
 
|-
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| 04.41
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| 04:41
 
|*In this, display the''' name, roll-no, total marks''' of the student.  
 
|*In this, display the''' name, roll-no, 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 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
  

Revision as of 12:53, 18 July 2014


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
00:11 *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 v. 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 upto 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 filename 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 are using 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 hypheno space abs
03:31 Press Enter
03:32 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,
04:04 Abstract class eg. class abstractinterface
04:09 Pure virtual function eg. 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 class 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, 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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