Difference between revisions of "C-and-C++/C2/Functions/English-timed"

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{| border = 1
 
{| border = 1
  
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|Time
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|'''Time'''
−
 
+
|'''Narration'''
−
|Narration
+
−
 
+
  
 
|-
 
|-
 
| 00:01
 
| 00:01
−
|Welcome to the spoken tutorial on '''Functions in C and C++'''
+
|Welcome to the spoken tutorial on '''Functions in C and C++'''.
  
 
|-
 
|-
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|-
 
|-
 
| 00:25
 
| 00:25
−
|'''Ubuntu Operating System''' version 11.10
+
|'''Ubuntu Operating System''' version 11.10,
  
 
|-
 
|-
 
|00:29
 
|00:29
 
| '''gcc''' and '''g++ Compiler''' version 4.6.1 .
 
| '''gcc''' and '''g++ Compiler''' version 4.6.1 .
−
 
  
 
|-
 
|-
 
|00:35
 
|00:35
−
|Let us start with the introduction to '''functions'''
+
|Let us start with the introduction to '''functions'''.
  
 
|-
 
|-
 
|00:39
 
|00:39
−
|A '''function'' is a self-contained program executing a specific task.  
+
|A '''function''' is a self-contained program executing a specific task.  
  
 
|-
 
|-
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|-
 
|-
 
| 00:55
 
| 00:55
−
|Let us see the syntax for '''function. '''
+
|Let us see the syntax for '''function.'''
  
 
|-
 
|-
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|-
 
|-
 
| 01:05
 
| 01:05
−
|'''fun_name''' defines the name of the '''function. '''
+
|'''fun_name''' defines the name of the function.  
−
 
+
  
 
|-
 
|-
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|01:32
 
|01:32
 
|So I will open it.  
 
|So I will open it.  
−
 
  
 
|-
 
|-
 
|01:35
 
|01:35
−
|Note that our filename is '''function. '''
+
|Note that our file name is '''function. '''
  
 
|-
 
|-
 
| 01:38
 
| 01:38
−
|And I have saved the file with the extentsion .c
+
|And I have saved the file with the extension '''.c''' (dot c).
  
 
|-
 
|-
 
| 01:43
 
| 01:43
 
|Let me explain the code.  
 
|Let me explain the code.  
−
 
  
 
|-
 
|-
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| 02:01
 
| 02:01
 
|There are two types of functions-  
 
|There are two types of functions-  
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 02:06
 
| 02:06
−
| '''Pre-defined''' that is '''printf''' and '''main function '''
+
| '''Pre-defined''' that is '''printf''' and '''main function '''.
−
 
+
  
 
|-
 
|-
 
| 02:12
 
| 02:12
−
| Here we have initialized '''a''' and '''b''' by assigning them values as 2 and 3  
+
| Here we have initialized '''a''' and '''b''' by assigning them values as 2 and 3.
  
 
|-
 
|-
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|-
 
|-
 
| 02:32
 
| 02:32
−
|Here we call the '''add function. '''
+
|Here we call the '''add''' function.
  
 
|-
 
|-
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|-
 
|-
 
| 02:53
 
| 02:53
−
|To compile, type '''gcc  function dot c  hyphen o  fun'''
+
|To compile, type '''gcc  function dot c  hyphen o  fun'''.
−
 
+
  
 
|-
 
|-
 
| 03:00
 
| 03:00
−
|To execute, type '''./fun''' (dot slash fun)
+
|To execute, type '''./fun''' (dot slash fun).
−
 
+
  
 
|-
 
|-
 
| 03:05
 
| 03:05
−
|We see the output is displayed as '''Sum of a and b is 5 '''
+
|We see the output is displayed as '''Sum of a and b is 5 '''.
−
 
+
  
 
|-
 
|-
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|-
 
|-
 
| 03:13
 
| 03:13
−
|Functions contains special identifiers called as '''parameters''' or '''arguments.'''  
+
|Functions contain special identifiers called as '''parameters''' or '''arguments.'''  
  
 
|-
 
|-
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| 03:27
 
| 03:27
 
|Type '''int add(int a, int b) '''
 
|Type '''int add(int a, int b) '''
−
 
  
 
|-
 
|-
 
| 03:32
 
| 03:32
 
|Here we have declared a '''function add. '''
 
|Here we have declared a '''function add. '''
−
 
  
 
|-
 
|-
 
| 03:36
 
| 03:36
−
|'''int a''' and '''int b''' are the '''arguments''' of the '''function add.'''  
+
|'''int a''' and '''int b''' are the '''arguments''' of the function  '''add.'''  
  
 
|-
 
|-
 
| 03:41
 
| 03:41
−
|Let us delete this.  
+
|Let us delete this.No need to initialize a and b here.  
−
 
+
−
|-
+
−
| 03:42
+
−
|No need to initialize a and b here.  
+
  
 
|-
 
|-
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| 03:49
 
| 03:49
 
|Type '''int main() '''
 
|Type '''int main() '''
−
 
  
 
|-
 
|-
 
| 03:52
 
| 03:52
 
| Let us declare a variable '''sum''' here.  
 
| Let us declare a variable '''sum''' here.  
−
 
  
 
|-
 
|-
 
| 03:54
 
| 03:54
 
|Type '''int sum; '''
 
|Type '''int sum; '''
−
 
  
 
|-
 
|-
 
| 03:57
 
| 03:57
 
|Then type '''sum = add(5,4); '''
 
|Then type '''sum = add(5,4); '''
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 04:20
 
| 04:20
−
|Hence type here  
+
|Hence type here '''printf(“Sum is %d\n”, sum);'''
−
 
+
−
|-
+
−
| 04:21
+
−
|'''printf(“Sum is %d\n”,sum);'''
+
  
 
|-
 
|-
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|-
 
|-
 
| 04:32
 
| 04:32
−
|Type return 0;  
+
|Type '''return 0;'''
−
 
+
  
 
|-
 
|-
 
| 04:36
 
| 04:36
 
|A '''non-void function''' must use a '''return''' statement that returns a value.  
 
|A '''non-void function''' must use a '''return''' statement that returns a value.  
−
 
  
 
|-
 
|-
 
| 04:41
 
| 04:41
−
|Click on '''Save'''
+
|Click on '''Save'''.
  
 
|-
 
|-
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| 04:50
 
| 04:50
 
|Let us execute.  
 
|Let us execute.  
−
 
  
 
|-
 
|-
 
| 04:52
 
| 04:52
−
|The output is displayed as '''Sum is 9 '''
+
|The output is displayed as '''Sum is 9 '''.
−
 
+
  
 
|-
 
|-
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| 05:04
 
| 05:04
 
|Let me change a few things here.  
 
|Let me change a few things here.  
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 05:18
 
| 05:18
−
|Click on '''Save'''.  
+
|Click on '''Save'''. First we will change the header file as <iostream>  
−
 
+
−
|-
+
−
| 05:19
+
−
|First we will change the header file as <iostream>  
+
−
 
+
  
 
|-
 
|-
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| 05:48
 
| 05:48
 
|We don't need the '''format specifier''' and '''\n''' here.  
 
|We don't need the '''format specifier''' and '''\n''' here.  
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 05:54
 
| 05:54
−
|Now, type two opening '''angle brackets'''
+
|Now, type two opening '''angle brackets'''.
  
 
|-
 
|-
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| 06:16
 
| 06:16
 
|Type '''g++ function dot cpp hyphen o fun1 '''
 
|Type '''g++ function dot cpp hyphen o fun1 '''
−
 
  
 
|-
 
|-
 
| 06:23
 
| 06:23
−
|Here we have fun1, this is because we don't want to overwrite the output file fun.  
+
|Here we have '''fun1''', this is because we don't want to overwrite the output file '''fun'''.  
−
 
+
  
 
|-
 
|-
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| 06:34
 
| 06:34
 
|Type '''./fun1 '''
 
|Type '''./fun1 '''
−
 
  
 
|-
 
|-
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| 06:55
 
| 06:55
 
|Click on '''Save.'''  
 
|Click on '''Save.'''  
 +
 
|-
 
|-
 
| 06:58
 
| 06:58
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|-
 
|-
 
| 07:06
 
| 07:06
−
|'''x was not declared in this scope. '''
+
|''' 'x' was not declared in this scope'''.
  
 
|-
 
|-
 
| 07:09
 
| 07:09
−
|This is because '''x''' is a '''character''' variable.
+
|This is because 'x' is a '''character''' variable.
  
 
|-
 
|-
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|-
 
|-
 
| 07:42
 
| 07:42
−
|Yes! it is working.  
+
|Yes! It is working.  
  
 
|-
 
|-
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|-
 
|-
 
| 07:55
 
| 07:55
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|Delete 4.  
+
|Delete 4. Click on '''Save'''.
−
 
+
−
|-
+
−
| 07:56
+
−
|Click on '''Save'''
+
  
 
|-
 
|-
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|-
 
|-
 
| 08:00
 
| 08:00
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| Let us compile.  
+
| Let us compile.We see an error at line no 10.  
−
 
+
−
|-
+
−
| 08:01
+
−
|We see an error at line no 10.  
+
  
 
|-
 
|-
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| 08:11
 
| 08:11
 
|Switch back to our program.  
 
|Switch back to our program.  
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 08:34
 
| 08:34
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|Switch to the '''terminal. '''
+
|Switch to the terminal.  
  
 
|-
 
|-
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|-
 
|-
 
| 08:39
 
| 08:39
−
|Yes it is working!
+
|Yes! It is working.
  
 
|-
 
|-
 
| 08:42
 
| 08:42
 
|Come back to our slides.  
 
|Come back to our slides.  
−
 
  
 
|-
 
|-
 
| 08:44
 
| 08:44
−
|To summarise, in this tutorial we have learnt -  
+
|To summarize, in this tutorial we have learnt -  
  
 
|-
 
|-
 
| 08:49
 
| 08:49
−
|'''Function'''
+
|'''function''' Syntax of '''function'''
−
 
+
−
|-
+
−
| 08:50
+
−
|Syntax of '''function'''
+
  
 
|-
 
|-
 
| 08:51
 
| 08:51
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|'''Function without arguments'''
+
|'''function without arguments'''
  
 
|-
 
|-
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|-
 
|-
 
| 08:57
 
| 08:57
−
|Eg- int add(int a and  int b)  
+
|Eg- int add(int a, int b)  
  
 
|-
 
|-
 
| 09:02
 
| 09:02
−
|As an assignment-  
+
|As an assignment- Write a program to calculate the square of a number.  
−
 
+
−
|-
+
−
| 09:03
+
−
|Write a program to calculate the square of a number.  
+
  
 
|-
 
|-
 
| 09:07
 
| 09:07
−
|Watch the video available at the link shown below
+
|Watch the video available at the link shown below.
  
 
|-
 
|-
 
| 09:11
 
| 09:11
−
|It summarizes the Spoken Tutorial project  
+
|It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
 
| 09:14
 
| 09:14
−
|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.
  
 
|-
 
|-
 
| 09:18
 
| 09:18
−
|The Spoken Tutorial Project Team  
+
|The Spoken Tutorial Project Team:
  
 
|-
 
|-
 
| 09:21
 
| 09:21
−
|Conducts workshops using spoken tutorials  
+
|Conducts workshops using spoken tutorials,
  
 
|-
 
|-
 
| 09:24
 
| 09:24
−
|Gives certificates to those who pass an online test  
+
|Gives certificates to those who pass an online test.
  
 
|-
 
|-
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|-
 
|-
 
|09:35
 
|09:35
−
|Spoken Tutorial Project is a part of Talk to a Teacher project  
+
|Spoken Tutorial Project is a part of Talk to a Teacher project.
  
 
|-
 
|-
 
| 09:40
 
| 09:40
−
|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.
−
 
+
  
 
|-
 
|-
 
| 09:47
 
| 09:47
−
|More information on this Mission is available at the link shown below
+
|More information on this Mission is available at the link shown below.
  
 
|-
 
|-
 
| 09:52
 
| 09:52
−
|This is Ashwini Patil from IIT Bombay  
+
|This is Ashwini Patil from IIT Bombay.
  
 
|-
 
|-
 
| 09:55
 
| 09:55
 
|Thank You for joining.
 
|Thank You for joining.

Latest revision as of 12:54, 24 March 2017

Time Narration
00:01 Welcome to the spoken tutorial on Functions in C and C++.
00:06 In this tutorial we will learn,
00:09 What is a function
00:11 Syntax of a function
00:13 Significance of return statement
00:16 We will do this through examples.
00:18 We will also see some common errors and their solutions.
00:22 To record this tutorial, I am using,
00:25 Ubuntu Operating System version 11.10,
00:29 gcc and g++ Compiler version 4.6.1 .
00:35 Let us start with the introduction to functions.
00:39 A function is a self-contained program executing a specific task.
00:45 Every program consists of one or more functions.
00:49 Once executed, the control will be returned back from where it was accessed.
00:55 Let us see the syntax for function.
00:59 ret-type defines the type of data that the function returns.
01:05 fun_name defines the name of the function.
01:09 parameters is the list of variable names and their types.
01:14 We can specify an empty parameter list.
01:18 This is called as functions without arguments.
01:21 And this is called as functions with arguments.
01:26 Let us see a program using void.
01:29 I have already typed the program on the editor.
01:32 So I will open it.
01:35 Note that our file name is function.
01:38 And I have saved the file with the extension .c (dot c).
01:43 Let me explain the code.
01:45 This is our header file.
01:47 Before using any function, it must be defined.
01:51 Here we have defined a function called add.
01:54 Note that add function is without any arguments.
01:58 And the return type is void.
02:01 There are two types of functions-
02:03 User-defined that is our add function and
02:06 Pre-defined that is printf and main function .
02:12 Here we have initialized a and b by assigning them values as 2 and 3.
02:19 Here we have declared a variable c.
02:21 Then we add the values of a and b.
02:24 The result is stored in c.
02:27 Then we print the result.
02:29 This is our main function.
02:32 Here we call the add function.
02:34 The addition operation will be performed and the result will be printed.
02:39 Now click on Save.
02:42 Let us execute the program.
02:45 Please open the terminal window by pressing Ctrl, Alt and T keys simultaneously.
02:53 To compile, type gcc function dot c hyphen o fun.
03:00 To execute, type ./fun (dot slash fun).
03:05 We see the output is displayed as Sum of a and b is 5 .
03:10 Now come back to our program.
03:13 Functions contain special identifiers called as parameters or arguments.
03:20 Let us see the same example with arguments.
03:23 I will change a few things here.
03:27 Type int add(int a, int b)
03:32 Here we have declared a function add.
03:36 int a and int b are the arguments of the function add.
03:41 Let us delete this.No need to initialize a and b here.
03:46 Delete the printf statement.
03:49 Type int main()
03:52 Let us declare a variable sum here.
03:54 Type int sum;
03:57 Then type sum = add(5,4);
04:03 Here we call the add function.
04:05 Then we pass the parameters as 5 and 4.
04:10 5 will be stored in a and 4 will be stored in b.
04:14 The addition operation will be performed.
04:18 Let us now print the result.
04:20 Hence type here printf(“Sum is %d\n”, sum);
04:27 Delete this, as we have already called the function above.
04:32 Type return 0;
04:36 A non-void function must use a return statement that returns a value.
04:41 Click on Save.
04:43 Let us execute the program.
04:45 Come back to our terminal.
04:48 Now compile the program as before.
04:50 Let us execute.
04:52 The output is displayed as Sum is 9 .
04:57 Now let us see how to execute the same program in C++.
05:02 Come back to our program.
05:04 Let me change a few things here.
05:07 First press Shift, Ctrl and S keys simultaneously.
05:12 Now save the file with .cpp extension.
05:18 Click on Save. First we will change the header file as <iostream>
05:24 We will include the using statement here.
05:28 The function declaration is same in C++.
05:32 So there is no need to change anything here.
05:37 Now replace the printf statement with the cout statement, as we use cout<< function to print a line in C++.
05:48 We don't need the format specifier and \n here.
05:52 Delete the comma.
05:54 Now, type two opening angle brackets.
05:58 After sum , again type two opening angle brackets.
06:03 Within double quotes, type backslash n.
06:07 Delete this closing bracket.
06:09 Now Click on Save.
06:11 Let us compile the program.
06:14 Come back to our terminal.
06:16 Type g++ function dot cpp hyphen o fun1
06:23 Here we have fun1, this is because we don't want to overwrite the output file fun.
06:31 Press Enter.
06:34 Type ./fun1
06:38 The output is displayed as: Sum is 9
06:42 Now we will see the common errors which we can come across.
06:47 Suppose here, we type x in place of 4.
06:51 I will retain the rest of the code as it is.
06:55 Click on Save.
06:58 Let us compile the program.
07:02 We see an error at line no. 10.
07:06 'x' was not declared in this scope.
07:09 This is because 'x' is a character variable.
07:13 It was not declared anywhere.
07:15 And our add function has integer variable as an argument.
07:21 So, there is a mismatch in return type and return value.
07:25 Now come back to our program.
07:27 Let us fix the error.
07:30 Type 4 at line no. 10.
07:32 Click on Save.
07:35 Let us execute again.
07:37 Let me clear the prompt.
07:40 Compile the program as before.
07:42 Yes! It is working.
07:45 Now we will see another common error which we can come across.
07:50 Suppose here we pass only one parameter.
07:55 Delete 4. Click on Save.
07:58 Switch to the terminal.
08:00 Let us compile.We see an error at line no 10.
08:06 too few arguments to function 'int add (int, int)'
08:11 Switch back to our program.
08:14 You can see here we have two parameters
08:19 int a and int b.
08:22 And here we are passing only one parameter.
08:25 Hence it is giving an error.
08:27 Let us fix the error.
08:29 Type 4.
08:31 Click on Save .
08:34 Switch to the terminal.
08:36 Let us execute again.
08:39 Yes! It is working.
08:42 Come back to our slides.
08:44 To summarize, in this tutorial we have learnt -
08:49 function Syntax of function
08:51 function without arguments
08:53 Eg- void add()
08:55 Function with arguments
08:57 Eg- int add(int a, int b)
09:02 As an assignment- Write a program to calculate the square of a number.
09:07 Watch the video available at the link shown below.
09:11 It summarizes the Spoken Tutorial project.
09:14 If you do not have good bandwidth, you can download and watch it.
09:18 The Spoken Tutorial Project Team:
09:21 Conducts workshops using spoken tutorials,
09:24 Gives certificates to those who pass an online test.
09:28 For more details, please write to, contact@spoken-tutorial.org
09:35 Spoken Tutorial Project is a part of Talk to a Teacher project.
09:40 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
09:47 More information on this Mission is available at the link shown below.
09:52 This is Ashwini Patil from IIT Bombay.
09:55 Thank You for joining.

Contributors and Content Editors

Ashwini, Kavita salve, Krupali, PoojaMoolya, Pratik kamble, Sandhya.np14

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