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

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|-
 
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|00:00  
 
|00:00  
|  Welcome to the spoken tutorial on Comments in '''Perl'''.  
+
|  Welcome to the spoken tutorial on '''Comments''' in '''Perl'''.  
  
 
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|-
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|00:08
 
|00:08
|Comments in '''Perl'''
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|comments in '''Perl'''.
  
 
|-
 
|-
 
|00:10
 
|00:10
|I am using '''Ubuntu Linux12.04''' operating system and '''Perl''' '''5.14.2 '''
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|I am using '''Ubuntu Linux 12.04''' operating system and '''Perl''' '''5.14.2 '''
  
 
|-
 
|-
 
|00:18
 
|00:18
|that is, '''Perl''' revision 5 version 14 and subversion 2
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|that is, '''Perl''' revision 5 version 14 and subversion 2.
  
 
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|00:31
 
|00:31
|You should have Basic knowledge of Compiling, Executing and Variables in Perl  
+
|You should have basic knowledge of compiling, executing and variables in Perl.
  
 
|-
 
|-
 
|00:37
 
|00:37
|If not, please go through the relevant spoken tutorials on the spoken tutorial website  
+
|If not, please go through the relevant spoken tutorials on the spoken tutorial website.
  
 
|-
 
|-
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|-
 
|-
 
| 00:47
 
| 00:47
|'''Single Line'''  
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|* '''Single Line'''  
  
 
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| 00:48
 
| 00:48
| ''' Multi Line'''
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|* ''' Multi Line'''.
 
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|00:49
 
|00:49
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|-
 
|00:55
 
|00:55
| to add one liner text to explain the functionality of a piece of code
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| to add one liner text to explain the functionality of a piece of code.
  
 
|-
 
|-
 
|01:01
 
|01:01
|This type of comment starts with the symbol ''' # (hash) '''.
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|This type of comment starts with the symbol '''# (hash)'''.
  
 
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|-
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| 01:19
 
| 01:19
|Once again, reminding you that the '''ampersand''' is used to free the '''command prompt''' in the '''terminal''' and press enter.
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|Once again reminding you that the ampersand is used to free the '''command prompt''' in the '''terminal''', now press '''Enter'''.
  
 
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|01:29
 
|01:29
|'''hash Declaring count variable''' 'press '''Enter'''
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|'''hash Declaring count variable''' press '''Enter'''.
  
 
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|-
 
|01:37
 
|01:37
|'''dollar count space equal to space 1 semicolon''' '''press enter'''
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|'''dollar count space equal to space 1 semicolon''' press '''Enter'''.
  
 
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|-
 
|01:45
 
|01:45
|'''print space double quotes Count is dollar count slash n''' close double quote '''semicolon space hash prints Count is 1'''
+
|'''print space double quotes Count is dollar count slash n''' double quotes complete '''semicolon space hash Prints Count is 1'''
  
 
|-
 
|-
 
|02:03
 
|02:03
| Now Save this file by pressing ctlr S  and execute the '''Perl''' script.
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| Now save this file by pressing '''Ctrl S''' and execute the '''Perl''' script.
  
 
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|02:18
 
|02:18
|This tells us that there is no syntax error
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|This tells us that there is no syntax error.
  
 
|-
 
|-
 
| 02:21
 
| 02:21
|Now type '''perl comments dot pl''' and press '''Enter.'''
+
|Now type: '''perl comments dot pl''' and press '''Enter.'''
  
 
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| 02:36
 
| 02:36
|In '''gedit''', go to the first line and press enter.
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|In '''gedit''', go to the first line and press '''Enter'''.
  
 
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| 02:52
 
| 02:52
|This line in '''Perl''' is called as a '''shebang''' '''line''' and is the first line in a '''Perl '''program.
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|This line in '''Perl''' is called as '''shebang line''' and is the first line in a '''Perl '''program.
  
 
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|03:03
 
|03:03
|'''Note:''' Though this line starts with hash symbol, it will not be considered as a single line comment by '''Perl'''.
+
|Note: Though this line starts with hash symbol, it will not be considered as a single line comment by '''Perl'''.
  
 
|-
 
|-
 
|03:11
 
|03:11
|Now let us look at multiline comments
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|Now let us look at multiline comments.
  
 
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| 03:13
 
| 03:13
|'''Multi Line''' This type of comment is used  
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|'''Multi Line:''' This type of comment is used  
  
 
|-
 
|-
 
|03:17
 
|03:17
|when user wants to comment a piece of code or  to add description/usage of piece of code
+
|when user wants to comment a piece of code or  to add description/usage of piece of code.
  
 
|-
 
|-
 
|03:25
 
|03:25
|This type of comment starts with the symbol '''equal to head''' and ends with '''equal to cut'''
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|This type of comment starts with the symbol '''equal to head''' and ends with '''equal to cut'''.
  
 
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|-
 
| 03:33
 
| 03:33
|Lets switch back to '''gedit''' and type the following in the '''comments dot pl '''file  
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|Let's switch back to '''gedit''' and type the following in the '''comments dot pl '''file.
  
 
|-
 
|-
 
|03:39
 
|03:39
|at the end of file type '''equal to head''', press '''Enter'''
+
|At the end of file, type: '''equal to head''', press '''Enter'''.
  
 
|-
 
|-
 
|03:45
 
|03:45
|'''print space double quote count variable is   used for counting purpose''' close double quote press enter.
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|'''print space double quote count variable is used for counting purpose''' double quote complete press '''Enter'''.
  
 
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| 04:05
 
| 04:05
| On the '''Terminal''', type '''perl hyphen c comments dot pl''' and press '''Enter'''.
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| On the '''Terminal''', type: '''perl hyphen c comments dot pl''' and press '''Enter'''.
  
 
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|-
 
|04:13
 
|04:13
|No syntax error
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|No syntax error.
  
 
|-
 
|-
 
| 04:15
 
| 04:15
| so let us execute it '''perl comments dot pl'''  
+
| So let us execute it, '''perl comments dot pl'''  
  
 
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| 04:21
 
| 04:21
|  It will show the same output as before. '''Count is 1'''
+
|  It will show the same output as before. '''Count is 1'''.
  
 
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|04:27
 
|04:27
|  It does not print the sentence '''“count variable is  used for counting purpose”'''
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|  It does not print the sentence “count variable is  used for counting purpose”.
  
 
|-
 
|-
 
|04:32
 
|04:32
| This is because we commented the portion using '''equal to head''' and '''equal to cut'''
+
| This is because we commented the portion using '''equal to head''' and '''equal to cut'''.
  
 
|-
 
|-

Revision as of 15:14, 7 May 2015

Time Narration
00:00 Welcome to the spoken tutorial on Comments in Perl.
00:05 In this tutorial, we will learn about
00:08 comments in Perl.
00:10 I am using Ubuntu Linux 12.04 operating system and Perl 5.14.2
00:18 that is, Perl revision 5 version 14 and subversion 2.
00:23 I will also be using the gedit Text Editor.
00:27 You can use any text editor of your choice.
00:31 You should have basic knowledge of compiling, executing and variables in Perl.
00:37 If not, please go through the relevant spoken tutorials on the spoken tutorial website.
00:43 Commenting a piece of code in Perl can be done in two ways:
00:47 * Single Line
00:48 * Multi Line.
00:49 This type of comment is used when user wants to comment a single line of code or
00:55 to add one liner text to explain the functionality of a piece of code.
01:01 This type of comment starts with the symbol # (hash).
01:05 Here is a demo. Let us open a new file in the Text Editor.
01:11 Open the Terminal and type - gedit comments dot pl space &
01:19 Once again reminding you that the ampersand is used to free the command prompt in the terminal, now press Enter.
01:27 Now type the following commands.
01:29 hash Declaring count variable press Enter.
01:37 dollar count space equal to space 1 semicolon press Enter.
01:45 print space double quotes Count is dollar count slash n double quotes complete semicolon space hash Prints Count is 1
02:03 Now save this file by pressing Ctrl S and execute the Perl script.
02:08 Switch to the Terminal, and type perl hyphen c comments dot pl and press Enter.
02:18 This tells us that there is no syntax error.
02:21 Now type: perl comments dot pl and press Enter.
02:28 It will show the following output - Count is 1
02:33 Let us switch back to gedit.
02:36 In gedit, go to the first line and press Enter.
02:40 Go back to the first line and type the following command.
02:44 Hash exclamation mark slash usr slash bin slash perl
02:52 This line in Perl is called as shebang line and is the first line in a Perl program.
02:59 It tells where to find the Perl Interpreter.
03:03 Note: Though this line starts with hash symbol, it will not be considered as a single line comment by Perl.
03:11 Now let us look at multiline comments.
03:13 Multi Line: This type of comment is used
03:17 when user wants to comment a piece of code or to add description/usage of piece of code.
03:25 This type of comment starts with the symbol equal to head and ends with equal to cut.
03:33 Let's switch back to gedit and type the following in the comments dot pl file.
03:39 At the end of file, type: equal to head, press Enter.
03:45 print space double quote count variable is used for counting purpose double quote complete press Enter.
03:59 equal to cut
04:01 Save the file, close it and execute the Perl script.
04:05 On the Terminal, type: perl hyphen c comments dot pl and press Enter.
04:13 No syntax error.
04:15 So let us execute it, perl comments dot pl
04:21 It will show the same output as before. Count is 1.
04:27 It does not print the sentence “count variable is used for counting purpose”.
04:32 This is because we commented the portion using equal to head and equal to cut.
04:40 You can either use =head =cut or =begin =end.
04:48 These are not the special keywords used by Perl.
04:52 Please note there should not be any leading or trailing space(s) before = to sign and after the head, cut, begin or end word.
05:02 Open the Terminal once again.
05:05 And Type - gedit commentsExample dot pl space & and press Enter.
05:15 Type the following commands as shown on the screen.
05:19 Here I am declaring two variables firstNum and secondNum and I am assigning some values to them.
05:28 Then I have commented this portion here.
05:32 Now I added these two numbers and assign the value to a third variable named addition.
05:39 Next I want to print the value using print command.
05:44 Save the file and execute the Perl script on the Terminal.
05:49 On terminal type perl hyphen c commentsExample dot pl, press Enter.
05:57 There is no syntax error
05:59 So execute the script by typing
06:01 perl commentsExample dot pl press enter
06:07 It will show the following output. Addition is 30
06:12 This brings us to the end of this tutorial.
06:16 Here we learnt, To Add Comments in Perl
06:19 Write a perl script to find square of a number.
06:23 Explain the functionality of the code written using: Single Line Comment & Mutli Line Comment.
06:30 Watch the video available at the following link
06:34 It summarises the Spoken Tutorial project
06:37 If you do not have good bandwidth, you can download and watch it
06:42 The Spoken Tutorial Project Team
06:44 Conducts workshops using spoken tutorials
06:48 Gives certificates to those who pass an online test
06:51 For more details, please write to contact at spoken hyphen tutorial dot org
06:58 Spoken Tutorial Project is a part of the Talk to a Teacher project
07:03 It is supported by the National Mission on Education through ICT, MHRD, Government of India
07:11 More information on this Mission is available at the following link.
07:15 Hope you enjoyed this Perl tutorial. This is Amol Brahmankar signing off.

Thanks for joining.

Contributors and Content Editors

Gaurav, Madhurig, PoojaMoolya, Sandhya.np14, Sneha