Difference between revisions of "PERL/C2/Functions-in-Perl/English-timed"

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| 00:01
 
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|Welcome to the spoken tutorial on ''' Functions in Perl'''.
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|Welcome to the spoken tutorial on ''' Functions in PERL'''.
  
 
|-
 
|-
 
| 00:06
 
| 00:06
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| In this tutorial, we will learn about -
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| In this tutorial, we will learn about:
  
 
|-
 
|-
 
|00:10
 
|00:10
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|''' Perl functions '''
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|* '''PERL functions'''  
 
   
 
   
 
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|-
 
|00:11
 
|00:11
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| ''' functions''' with '''arguments '''
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|* '''functions''' with '''arguments'''
 
   
 
   
 
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|00:13
 
|00:13
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|''' function''' with '''return values'''  
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|* ''' function''' with '''return values'''.
  
 
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| ''' Ubuntu Linux12.04''' operating system  
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|* '''Ubuntu Linux 12.04''' operating system  
  
 
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| 00:22
 
| 00:22
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|''' Perl 5.14.2''' and  
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|* ''' Perl 5.14.2''' and  
  
 
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| 00:24
 
| 00:24
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| ''' gedit''' Text Editor  
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|* ''' gedit''' Text Editor.
  
 
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|00:31
 
|00:31
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|You should have basic knowledge of ''' variables, comments, loops, conditional statements''' and ''' Data Structures''' in '''Perl.'''
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|You should have basic knowledge of ''' variables, comments, loops, conditional statements''' and '''data Structures''' in PERL.
 
   
 
   
 
|-
 
|-
 
| 00:41
 
| 00:41
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| Please go through the relevant spoken tutorials on the ''' spoken tutorial''' website.   
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| Please go through the relevant spoken tutorials on the '''spoken tutorial''' website.   
 
   
 
   
 
|-
 
|-
 
|00:47
 
|00:47
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|We will first see some simple ''' Perl functions.'''
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|We will first see some simple '''PERL functions.'''
  
 
|-
 
|-
 
|00:51
 
|00:51
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|In ''' Perl, functions''', also called as ''' subroutines''', are declared with ''' sub keyword.'''
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|In PERL, '''functions''', also called as ''' subroutines''', are declared with '''sub''' keyword.
  
 
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| 00:57
 
| 00:57
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| The definition of a declared ''' function''' is written between curly braces.  
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| The definition of a declared function is written between curly braces.  
  
 
|-
 
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|01:03
 
|01:03
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|This ''' function''' does not take any ''' arguments.'''  
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|This function does not take any ''' arguments.'''  
  
 
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|01:07
 
|01:07
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| And, it does not return anything.  
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| And, it does not '''return''' anything.  
 
   
 
   
 
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|01:10
 
|01:10
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|Note: ''' function''' definition can be written anywhere in the script or in another '''module'''.  
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|Note: function definition can be written anywhere in the script or in another '''module'''.  
  
 
|-
 
|-
 
|01:17
 
|01:17
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|This ''' module''', must then be included in the script, to use this ''' function.'''
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|This '''module''' must then be included in the script, to use this function.  
 
   
 
   
 
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|01:24
 
|01:24
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|To include the ''' module ''' file in the script, one has to use the following syntax-  
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|To include the '''module''' file in the script, one has to use the following syntax-  
  
 
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|''' functions''' which '''return values''' using sample programs.  
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|'''functions''' which '''return values''' using sample programs.  
  
 
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|09:27
 
|09:27
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|Here is assignment for you -
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|Here is assignment for you: 
  
 
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|Perform some action on these '''arguments '''
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|Perform some action on these '''arguments'''.
  
 
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|09:43
 
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|Watch the video available at the following link
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|Watch the video available at the following link.
  
 
|-
 
|-
 
|09:47
 
|09:47
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|It summaries the Spoken Tutorial project
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|It summaries the Spoken Tutorial project.
 
   
 
   
 
|-
 
|-
 
|09:51
 
|09:51
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|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.
 
   
 
   
 
|-
 
|-
 
| 09:56
 
| 09:56
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|  The Spoken Tutorial Project Team  Conducts workshops using spoken tutorials
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|  The Spoken Tutorial project team: Conducts workshops using spoken tutorials.
 
   
 
   
 
|-
 
|-
 
|10:02
 
|10:02
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|Gives certificates to those who pass an online test
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|Gives certificates to those who pass an online test.
 
   
 
   
 
|-
 
|-
 
|10:07
 
|10:07
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|For more details, please write to contact at spoken hyphen tutorial dot org
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|For more details, please write to contact at: spoken hyphen tutorial dot org.
 
   
 
   
 
|-
 
|-
 
| 10:14
 
| 10:14
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|  Spoken Tutorial Project is a part of the Talk to a Teacher project
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|  "Spoken Tutorial" project is a part of the "Talk to a Teacher" project.
 
   
 
   
 
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|10:28
 
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|More information on this Mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro
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|More information on this mission is available at: spoken hyphen tutorial dot org slash NMEICT hyphen Intro.
 
   
 
   
 
|-
 
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| 10:40
 
| 10:40
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| Hope you enjoyed this Perl tutorial.  
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| Hope you enjoyed this PERL tutorial.  
 
   
 
   
 
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|10:43
 
|10:43
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|This is Amol signing off.
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|This is Amol, signing off.
 
   
 
   
 
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|-

Revision as of 18:30, 13 May 2015

Time Narration
00:01 Welcome to the spoken tutorial on Functions in PERL.
00:06 In this tutorial, we will learn about:
00:10 * PERL functions
00:11 * functions with arguments
00:13 * function with return values.
00:16 For this tutorial, I am using
00:18 * Ubuntu Linux 12.04 operating system
00:22 * Perl 5.14.2 and
00:24 * gedit Text Editor.
00:27 You can use any text editor of your choice.
00:31 You should have basic knowledge of variables, comments, loops, conditional statements and data Structures in PERL.
00:41 Please go through the relevant spoken tutorials on the spoken tutorial website.
00:47 We will first see some simple PERL functions.
00:51 In PERL, functions, also called as subroutines, are declared with sub keyword.
00:57 The definition of a declared function is written between curly braces.
01:03 This function does not take any arguments.
01:07 And, it does not return anything.
01:10 Note: function definition can be written anywhere in the script or in another module.
01:17 This module must then be included in the script, to use this function.
01:24 To include the module file in the script, one has to use the following syntax-
01:31 use ModuleFileName semicolon
01:35 Let us understand this using a sample program.
01:39 Open a file in your text editor and name it as simpleFunction dot pl
01:46 Here is my simpleFunction dot pl file in gedit.
01:51 Type the code as displayed on the screen.
01:55 Here, we are just calling a function, which we have defined.
02:00 Then, the execution control is passed to that function.
02:06 This is the declaration & definition of the function.
02:10 This function will print out the given text.
02:14 Save your file.
02:17 Then switch to the terminal and execute the Perl script by typing
02:24 perl simpleFunction dot pl
02:28 and press Enter.
02:30 The output will be as shown on the terminal
02:38 Now, let us see a function with arguments.
02:44 Let us understand this function using a sample program.
02:48 Open a file in your text editor and name it as functionWithArgs dot pl
02:57 Here is my functionWithArgs script in gedit.
03:02 Type the following piece of code as shown on the screen.
03:07 Here, we are calling a function with arguments, 10 and 20.
03:13 The passed arguments are caught in $var1 & $var2.
03:20 @_ is a special Perl variable. We will cover its details in future tutorials.
03:29 This function performs the addition of 2 variables and prints the answer.
03:37 Save your file.
03:42 @_ is a special Perl array.
03:46 This array is used to store the passed arguments.
03:51 Similarly, we can catch the passed arguments in variables as
03:56 $var1 space = space shift @_ semicolon
04:04 $var2 space = space shift @_ semicolon
04:12 shift @_ removes the element at first position from @_ array
04:21 and assigns it to a variable
04:24 Another way is; $var1 space = space dollar underscrore open square bracket zero close square bracket semicolon
04:38 $var2 space = space dollar underscrore open square bracket 1 close square bracket semicolon
04:49 The above mentioned way is similar to fetching elements of @_ array using index.
04:59 Now, switch to terminal and execute the script by typing -
05:06 perl functionWithArgs dot pl and press Enter
05:14 The output is as displayed on the screen
05:23 Now, let us look at a functions which returns a single value.
05:32 Let us understand the same using a sample program.
05:35 Let me switch to funcWithSingleRtrnVal dot pl script in gedit.
05:46 Open a file in your text editor and type the following piece of code as shown.
05:52 Here, we are calling addVariables function with parameters 10 and 20.
06:01 The return value of the function is caught in $addition variable.
06:09 This function does the addition of the passed parameters and returns the answer.
06:15 Save the file.
06:17 Now let us execute the script.
06:20 So, switch to terminal and type-
06:24 perl funcWithSingleRtrnVal dot pl and press Enter.
06:35 The output is as displayed on the terminal.
06:43 Now, let us see a function which returns multiple values.
06:48 Let us understand the same, using a sample program.
06:53 In gedit, I have opened a file and named it as funcWithMultipleRtrnVals dot pl
07:04 Please do like wise in your text editor
07:08 Now, type the following piece of code as shown.
07:13 Here, we are calling addVariables function with parameters 10 and 20.
07:21 The return values of the function are caught in variables $var1, $var2 and $addition
07:31 This function does the addition and returns the passed parameters and the resultant answer.
07:42 This illustration demonstrates how we can return an array from a function.
07:53 Similarly, this demonstrates how hash can be returned from a function.
08:00 Save your file.
08:03 Now let us execute the Perl script on the terminal by typing -
08:10 perl funcWithMultipleRtrnVals dot pl
08:18 and press Enter.
08:20 The output is as displayed on the terminal.
08:32 Perl provides several inbuilt functions.
08:36 We learnt some of them in earlier tutorials. For eg- Arrays, Hash, sort, scalar, each, keys etc.
08:49 Calling inbuilt functions, similar to calling any other function, which we define.
08:57 E.g sort open bracket @arrayName close bracket semicolon
09:04 Try incorporating some inbuilt functions in the sample programs we used.
09:10 And observe their outputs.
09:13 Let us summarize.
09:15 In this tutorial, we have learnt -
09:17 Functions in Perl
09:19 functions with arguments and
09:22 functions which return values using sample programs.
09:27 Here is assignment for you:
09:29 Write a function which takes 3 arguments.
09:33 Perform some action on these arguments.
09:37 Return the result of the action performed on the arguments and print the same.
09:43 Watch the video available at the following link.
09:47 It summaries the Spoken Tutorial project.
09:51 If you do not have good bandwidth, you can download and watch it.
09:56 The Spoken Tutorial project team: Conducts workshops using spoken tutorials.
10:02 Gives certificates to those who pass an online test.
10:07 For more details, please write to contact at: spoken hyphen tutorial dot org.
10:14 "Spoken Tutorial" project is a part of the "Talk to a Teacher" project.
10:19 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
10:28 More information on this mission is available at: spoken hyphen tutorial dot org slash NMEICT hyphen Intro.
10:40 Hope you enjoyed this PERL tutorial.
10:43 This is Amol, signing off.
10:46 Thanks for joining.

Contributors and Content Editors

Gaurav, PoojaMoolya, Sandhya.np14

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