PERL/C2/Functions-in-Perl/English - Revision history

Nancyvarkey at 12:53, 7 January 2014

2014-01-07T12:53:00Z

AmolBrahmankar: Created page with ''''Title Of Script: Functions in Perl''' '''Author: Amol Brahmankar''' '''Keywords: Functions in Perl, video tutorial, sub, subroutine, function without arguments or return val…'

2013-11-18T12:14:15Z

Created page with ''''Title Of Script: Functions in Perl''' '''Author: Amol Brahmankar''' '''Keywords: Functions in Perl, video tutorial, sub, subroutine, function without arguments or return val…'

New page

'''Title Of Script: Functions in Perl'''

'''Author: Amol Brahmankar'''

'''Keywords: Functions in Perl, video tutorial, sub, subroutine, function without arguments or return value, function with arguments, function with a single return value, function with a multiple return values'''

{| style="border-spacing:0;"
| style="border-top:0.0007in solid #000000;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| <center>'''Visual Cue'''</center>
| style="border:0.0007in solid #000000;padding:0.0382in;"| <center>'''Narration'''</center>

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Welcome to the spoken tutorial on '''Functions''' in''' Perl.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide: Learning Objectives
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| In this tutorial, we will learn about -

* '''Perl functions'''
* '''functions''' with '''arguments'''
* '''function '''with '''return values'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide: System Requirements
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| For this tutorial, I am using

* '''Ubuntu Linux12.04''' operating system
* '''Perl 5.14.2'''
* and the '''gedit '''Text Editor

You can use any text editor of your choice.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide: Prerequisites
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| You should have basic knowledge of '''variables, comments, loops, conditional statements '''and''' Data Structures '''in''' Perl.'''

Please go through the relevant spoken tutorials on the '''spoken tutorial '''website.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| We will first see some simple''' Perl functions.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| '''sub simple_func {'''

'''<nowiki># piece of code</nowiki>'''

'''} '''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| * In '''Perl''', '''functions,''' also called as '''subroutines,''' are declared with '''sub''' '''keyword.'''
* The definition of a declared '''function''' is written between curly braces.
* This '''function''' does not take any '''arguments.'''
* And, it does not return anything.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| '''Note: '''

* '''function '''definition can be written anywhere in the script or in another '''module.'''
* This '''module''', must''' '''then be included in the script, to use this '''function.'''
* To include the '''module '''file in the script, one has to use the following syntax-

'''use ModuleFileName;'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us understand this using asample program.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Directly switch to the file in '''gedit'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Open a file in your text editor and name it as '''simpleFunction dot pl'''

Here is my '''simpleFunction dot pl''' file in '''gedit'''.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| In '''gedit'''

'''<nowiki>#!/usr/bin/perl </nowiki>'''

'''<nowiki># Call the function</nowiki>'''

'''printText();'''

'''sub printText {'''

'''print “This is illustration of simple Perl Function\n”;'''

'''}'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Type the code as displayed on the screen.

<nowiki><<pause>></nowiki>

Here, we are just calling a '''function, '''which we have defined.

Then, the execution control is passed to that '''function.'''

This is the declaration & definition of the '''function'''. This '''function''' will print out the given text.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Save your file.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Switch to terminal

'''perl simpleFunction.pl'''

| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Then switch to the '''terminal '''and '''execute '''the '''Perl''' script by typing

'''perl simpleFunction dot pl'''

and press''' Enter.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Highlight the output on the terminal

'''This is illustration of simple Perl Function'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| <nowiki>The output will be as shown <<pause>></nowiki>

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now, let us '''see '''a '''function '''with '''arguments.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| '''sub func_with_parameters {'''

'''($variable1, $variable2,...$variableN) = @_;'''

'''<nowiki># Action to be perform on the arguments pass to this function</nowiki>'''

'''}'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us understand this '''function''' using a sample program.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Directly switch to the file in '''gedit'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Open a file in your text editor and name it as '''functionWithArgs''' '''dot pl'''

Here is my '''functionWithArgs''' script in '''gedit'''.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Gedit

'''<nowiki>#!/usr/bin/perl </nowiki>'''

'''<nowiki># Call the function</nowiki>'''

'''addVariables(10, 20);'''

'''sub addVariables {'''

'''($var1, $var2) = @_;'''

'''$addition = $var1 + $var2;'''

'''print “Addition is: $addition\n”;'''

'''}'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Type the following piece of code as shown on the screen.

<nowiki><<pause>></nowiki>

Here, we are calling a '''function''' with two '''arguments, 10''' and''' 20'''.

* The passed arguments are caught in '''$var1 '''& '''$var2.'''
* '''@_''' is a special '''Perl variable. '''We will''' '''cover its details in future tutorials.
* This '''function''' performs the addition of 2 '''variables''' and prints the answer.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Save your file.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Note:

* '''@_ '''is a''' special Perl array'''.
* This '''array''' is used to store the passed '''arguments'''.
* Similarly, we can catch the passed '''arguments''' in '''variables''' as

'''$var1 = shift @_;'''

'''$var2 = shift @_;'''

* '''shift @_ '''removes the '''element '''at '''first position '''from '''@_ array''' and assigns it to a '''variable'''.
* Another way is;<br/> '''<nowiki>$var1 = $_[0];</nowiki>'''<br/> '''<nowiki>$var2 = $_[1];</nowiki>'''
* The above mentioned way is similar to fetching '''elements''' of '''@_ array''' using '''index.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Terminal

'''Addition is: 30'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now, switch to '''terminal '''and execute the script

by typing -

'''perl functionWithArgs dot pl'''

and press''' Enter'''

The output is as displayed on the '''terminal.'''

<nowiki><pause>></nowiki>

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now, let us look at a '''functions''' which returns a single value.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| '''sub return_single_value {'''

'''<nowiki>#piece of code </nowiki>'''

'''return $variable;'''

'''}'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us understand the same using a sample program.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Directly switch to the file in '''gedit'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let me switch to '''funcWithSingleRtrnVal dot pl''' script in '''gedit.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Gedit

'''<nowiki>#!/usr/bin/perl </nowiki>'''

'''<nowiki># Call the function</nowiki>'''

'''$addition = addVariables(10, 20);'''

'''print “Addition is: $addition\n”;'''

'''sub addVariables {'''

'''($var1, $var2) = @_;'''

'''$add = $var1 + $var2;'''

'''return $add;'''

'''}'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Open a file in your text editor and type the following piece of code as shown.

<nowiki><<pause>></nowiki>

Here, we are calling '''addVariables function '''with '''parameters 10 '''and '''20. '''

The return value of the '''function '''is caught in '''$addition variable.'''

This '''function''' does the addition of the passed '''parameters''' and returns the answer.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Save the file.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Terminal

'''perl funcWithSingleRtrnVal.pl'''

'''Addition is: 30'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now let us execute the script. So, switch to '''terminal '''and type-

'''perl funcWithSingleRtrnVal dot pl'''

and press '''Enter'''

The output is as displayed on the '''terminal'''

<nowiki><pause>></nowiki>

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now, let us see a '''function''' which returns multiple values.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| '''sub return_multiple_values {'''

'''<nowiki>#piece of code </nowiki>'''

'''return ($variable1, $variable2,...$variableN);'''

'''}'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us understand the same, using a sample program.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Directly switch to the file in '''gedit'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| In '''gedit, '''I have opened a file and named it as '''funcWithMultipleRtrnVals dot pl'''

Pls do likewise in your text editor.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Gedit

'''<nowiki>#!/usr/bin/perl </nowiki>'''

'''use Data::Dumper; '''

'''<nowiki># Call the function </nowiki>'''

'''($var1, $var2, $addition) = addVariables(10, 20); '''

'''print "Addition of $var1 and $var2 is: $addition\n"; '''

'''sub addVariables { '''

'''($var1, $var2) = @_; '''

'''$add = $var1 + $var2; '''

'''return ($var1, $var2, $add); '''

'''} '''

'''@marksArray = getMarksArray(); '''

'''print "Array\n"; '''

'''print Dumper \@marksArray; '''

'''%marksHash = getMarksHash(); '''

'''print "Hash\n"; '''

'''print Dumper \%marksHash; '''

'''sub getMarksArray { '''

'''@mArray = (98, 96, 95); '''

'''return @mArray; '''

'''} '''

'''sub getMarksHash { '''

'''%mHash = ( '''

''''English' => 98, '''

''''Physics' => 96, '''

''''Chemistry' => 95 '''

'''); '''

'''return %mHash; '''

'''}'''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now, type the following piece of code as shown.

<nowiki><<pause>></nowiki>

Here, we are calling '''addVariables function''' with '''parameters''' '''10''' and '''20'''.

The return values of the '''function''' are caught in '''variables''' '''$var1, $var2''', '''$addition'''.

This '''function''' does addition and returns the passed parameters and the resultant answer.

This illustration demonstrates how we can return an '''array '''from a '''function.'''

Similarly this demonstrates how '''hash''' can be returned from a '''function.'''

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Press ctrl + s
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Save your file.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Terminal

'''Addition of 10 and 20 is: 30 '''

'''Array '''

'''<nowiki>$VAR1 = [ </nowiki>'''

'''98, '''

'''96, '''

'''95 '''

''']; '''

'''Hash '''

'''$VAR1 = { '''

''''Chemistry' => 95, '''

''''English' => 98, '''

''''Physics' => 96 '''

'''}; '''
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now let us execute the '''Perl '''script on the '''terminal '''by typing -

'''perl funcWithMultipleRtrnVals dot pl'''

and press''' Enter.'''

The output is as displayed on the '''terminal.'''

<nowiki><pause>></nowiki>

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| '''Perl''' provides several '''inbuilt functions.'''

We learnt some of them in earlier tutorials. For eg-''' Arrays, Hash, sort, scalar, each, keys '''etc..

Calling '''inbuilt''' '''functions''', similar to calling any other '''function, '''which we define.

E.g '''sort(@arrayName);'''

Try some incorporating some''' inbuilt functions''' in the sample programs we used.

And observe their outputs.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide: Summary
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us summarize.

In this tutorial, we have learnt -

* '''Functions '''in''' Perl'''
* '''functions''' with '''arguments '''and
* '''functions '''which''' return values'''

using sample programs.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Slide: Assignment
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Here is assignment for you -

# Write a '''function''' which takes 3 '''arguments'''.
# Perform some action on these '''arguments'''
# Return the result of the action performed on the '''arguments '''and print the same.

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| About the Project
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Watch the video available at the following link

It summaries the Spoken Tutorial project

If you do not have good bandwidth, you can

download and watch it

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Spoken Tutorial Workshops
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| The Spoken Tutorial Project Team

Conducts workshops using spoken tutorials

Gives certificates to those who pass an online

test

For more details, please write to

contact at spoken hyphen tutorial dot org

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"| Acknowledgment

http://spoken-tutorial.org\NMEICT-Intro
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Spoken Tutorial Project is a part of the Talk to a

Teacher project

It is supported by the National Mission on

Education through ICT, MHRD, Government of India.

More information on this Mission is available

spoken hypen tutorial dot org slash NMEICT hyphen Intro

|-
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Hope you enjoyed this '''Perl''' tutorial.

This is Amol Brahmankar signing off.

Thanks for joining

|}

@@ Line 69: / Line 69: @@
 * '''function '''definition can be written anywhere in the script or in another '''module.'''
 * This '''module''', must''' '''then be included in the script, to use this '''function.'''
-* To include the '''module '''file in the script, one has to use the following syntax-
 '''use ModuleFileName;'''
@@ Line 75: / Line 79: @@
 |-
 | style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:none;padding:0.0382in;"|
-| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us understand this using asample program.
+| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Let us understand this using a sample program.
 |-
@@ Line 111: / Line 115: @@
-This is the declaration & definition of the '''function'''. This '''function''' will print out the given text.
+This is the declaration & definition of the '''function'''.
 |-
@@ Line 197: / Line 203: @@
-* The passed arguments are caught in '''$var1 '''& '''$var2.'''
+* The passed '''arguments''' are caught in '''$var1 '''& '''$var2.'''
 * '''@_''' is a special '''Perl variable. '''We will''' '''cover its details in future tutorials.
 * This '''function''' performs the addition of 2 '''variables''' and prints the answer.
@@ Line 219: / Line 225: @@
 '''$var2 = shift @_;'''
-* '''shift @_ '''removes the '''element '''at '''first position '''from '''@_ array''' and assigns it to a '''variable'''.
+* '''shift @_ '''removes the '''element '''at '''first position '''from '''@_ array'''
 * Another way is;<br/> '''<nowiki>$var1 = $_[0];</nowiki>'''<br/> '''<nowiki>$var2 = $_[1];</nowiki>'''
 * The above mentioned way is similar to fetching '''elements''' of '''@_ array''' using '''index.'''
@@ Line 315: / Line 322: @@
 '''Addition is: 30'''
-| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now let us execute the script. So, switch to '''terminal '''and type-
+| style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| Now let us execute the script.
 '''perl funcWithSingleRtrnVal dot pl'''
-and press '''Enter'''
+and press '''Enter'''.
-The output is as displayed on the '''terminal'''
+The output is as displayed on the '''terminal'''.
 <nowiki><pause>></nowiki>
@@ Line 350: / Line 359: @@
 | style="border-top:none;border-bottom:0.0007in solid #000000;border-left:0.0007in solid #000000;border-right:0.0007in solid #000000;padding:0.0382in;"| In '''gedit, '''I have opened a file and named it as '''funcWithMultipleRtrnVals dot pl'''
 |-
@@ Line 425: / Line 432: @@
 Here, we are calling '''addVariables function''' with '''parameters''' '''10''' and '''20'''.
 The return values of the '''function''' are caught in '''variables''' '''$var1, $var2''', '''$addition'''.
 This '''function''' does addition and returns the passed parameters and the resultant answer.
@@ Line 436: / Line 448: @@
 Similarly this demonstrates how '''hash''' can be returned from a '''function.'''
 |-
@@ Line 499: / Line 542: @@
-Try some incorporating some''' inbuilt functions''' in the sample programs we used.
+Try incorporating some''' inbuilt functions''' in the sample programs we used.