Nancyvarkey at 07:53, 23 March 2017

2017-03-23T07:53:06Z

Nancyvarkey at 07:29, 23 March 2017

2017-03-23T07:29:12Z

Nancyvarkey: Created page with "{| border = 1 |'''Time''' |'''Narration''' |- | 00:01 |Welcome to the spoken tutorial on '''Functions in C and C++'''. |- | 00:06 |In this tutorial we will learn, |- |..."

2015-04-10T11:00:23Z

Created page with "{| border = 1 |'''Time''' |'''Narration''' |- | 00:01 |Welcome to the spoken tutorial on '''Functions in C and C++'''. |- | 00:06 |In this tutorial we will learn, |- |..."

New page

{| border = 1

|'''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. '''

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| 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.'''

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|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-

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| 02:03
| '''User-defined''' that is our '''add function''' and

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| 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. '''

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| 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.

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| 02:29
| This is our '''main function. '''

|-
| 02:32
|Here we call the '''add''' function.

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| 02:34
|The addition operation will be performed and the result will be printed.

|-
| 02:39
| Now click on '''Save.'''

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| 02:42
|Let us execute the program.

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| 02:45
|Please open the terminal window by pressing '''Ctrl, Alt''' and '''T ''' keys simultaneously.

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| 02:53
|To compile, type '''gcc function dot c hyphen o fun'''.

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| 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.

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| 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.

|-
| 03:42
|No need to initialize a and b here.

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| 03:46
|Delete the '''printf '''statement.

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| 03:49
|Type '''int main() '''

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| 03:52
| Let us declare a variable '''sum''' here.

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| 03:54
|Type '''int sum; '''

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| 03:57
|Then type '''sum = add(5,4); '''

|-
| 04:03
|Here we call the '''add function.'''

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| 04:05
|Then we pass the parameters as 5 and 4.

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| 04:10
|5 will be stored in '''a''' and 4 will be stored in ''' b. '''

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| 04:14
|The addition operation will be performed.

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| 04:18
|Let us now print the result.

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| 04:20
|Hence type here

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| 04:21
|'''printf(“Sum is %d\n”, sum);'''

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| 04:27
|Delete this, as we have already called the function above.

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| 04:32
|Type '''return 0;'''

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| 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.

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| 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.

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| 05:07
|First press '''Shift, Ctrl and S''' keys simultaneously.

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| 05:12
|Now save the file with '''.cpp''' extension.

|-
| 05:18
|Click on '''Save'''.

|-
| 05:19
|First we will change the header file as <iostream>

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| 05:24
|We will include the '''using''' statement here.

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| 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'''.

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| 05:58
|After sum , again type two opening '''angle brackets'''.

|-
| 06:03
|Within double quotes, type '''backslash n'''.

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| 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. '''

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| 06:34
|Type '''./fun1 '''

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| 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.

|-
| 07:56
|Click on '''Save'''.

|-
| 07:58
|Switch to the terminal.

|-
| 08:00
| Let us compile.

|-
| 08:01
|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'''

|-
| 08:50
|*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-

|-
| 09:03
|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 Jean Bonnet from IIT Bombay.

|-
| 09:55
|Thank You for joining.

@@ Line 233: / Line 233: @@
 |-
-| 03:42
+| 03:43
 |No need to initialize a and b here.
@@ Line 281: / Line 281: @@
 |-
-| 04:21
+| 04:22
 |'''printf(“Sum is %d\n”, sum);'''
@@ Line 509: / Line 509: @@
 |-
-| 07:56
+| 07:57
 |Click on '''Save'''.
 |-
-| 07:58
+| 07:59
 |Switch to the terminal.
 |-
-| 08:00
+| 08:01
 | Let us compile.
 |-
-| 08:01
+| 08:03
 |We see an error at line no 10.
@@ Line 581: / Line 581: @@
 |-
-| 08:49
+| 08:48
 |'''function'''
@@ Line 589: / Line 589: @@
 |-
-| 08:51
+| 08:52
 |'''function without arguments'''
 |-
-| 08:53
+| 08:54
 |Eg- void add()
 |-
-| 08:55
+| 08:56
 |Function with arguments
 |-
-| 08:57
+| 08:58
 |Eg- int add(int a, int b)
 |-
 | 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.
 |-

@@ Line 14: / Line 14: @@
 |-
 | 00:09
-|* What is a '''function'''
+|What is a '''function'''
 |-
 | 00:11
-|* Syntax of a '''function'''
+|Syntax of a '''function'''
 |-
 | 00:13
-|*Significance of '''return statement'''
+|Significance of '''return statement'''
 |-
@@ Line 582: / Line 582: @@
 |-
 | 08:49
-|*'''function'''
+|'''function'''
 |-
 | 08:50
-|*Syntax of '''function'''
+|Syntax of '''function'''
 |-
 | 08:51
-|*'''function without arguments'''
+|'''function without arguments'''
 |-

C-and-Cpp/C2/Functions/English-USA - Revision history

Nancyvarkey at 07:53, 23 March 2017

Nancyvarkey at 07:29, 23 March 2017

Nancyvarkey: Created page with "{| border = 1 |'''Time''' |'''Narration''' |- | 00:01 |Welcome to the spoken tutorial on '''Functions in C and C++'''. |- | 00:06 |In this tutorial we will learn, |- |..."