Difference between revisions of "PERL/C2/Conditional-statements/English-timed"

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(Created page with '{| border=1 ! <center>'''Visual Cue'''</center> ! <center>'''Narration'''</center> |- | 00.01 |Welcome to the spoken tutorial on if and if-else conditional statements in Perl…')
 
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|00.09
 
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  |if statement and  
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  |'''if ''' statement and  
  
 
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|00.11
 
|00.11
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  |if-else statement in Perl  
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  |''' if-else''' statement in Perl  
 
   
 
   
 
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|00.49
 
|00.49
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|if
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|'''if'''
 
   
 
   
 
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|00.50
 
|00.50
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|if-else  
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|'''if-else '''
 
   
 
   
 
|-
 
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|00.51
 
|00.51
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|if-elsif-else and  
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|'''if-elsif-else''' and  
 
   
 
   
 
|-
 
|-
 
|00.53
 
|00.53
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|switch  
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|'''switch '''
 
   
 
   
 
   
 
   
 
|-
 
|-
 
|00.54
 
|00.54
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|In this tutorial, we'll cover if and If-else statements  
+
|In this tutorial, we'll cover '''if '''and '''If-else''' statements  
 
   
 
   
 
|-
 
|-
 
|00.59
 
|00.59
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|if statement in Perl can be used  
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|'''if'''  statement in '''Perl''' can be used  
 
   
 
   
 
|-
 
|-
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|-
 
|-
 
|01.07
 
|01.07
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|The syntax of if conditional statement is as follows  
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|The syntax of '''if''' conditional statement is as follows  
 
   
 
   
 
   
 
   
 
|-
 
|-
 
|01.11
 
|01.11
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|if space open bracket condition close bracket space Open curly bracket  
+
|'''if '''space open bracket '''condition''' close bracket space Open curly bracket  
 
   
 
   
 
   
 
   
 
|-
 
|-
 
|01.19
 
|01.19
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|Enter
+
|'''Enter'''
 
   
 
   
 
|-
 
|-
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|-
 
|-
 
|01.25
 
|01.25
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| Enter, Close curly bracket
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| '''Enter''', Close curly bracket
 
   
 
   
 
   
 
   
 
|-
 
|-
 
|01.29
 
|01.29
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|The code inside the if statement will be executed only when the condition is true.  
+
|The code inside the '''if''' statement will be executed only when the condition is true.  
 
   
 
   
 
|-
 
|-
 
|01.36
 
|01.36
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| Now let us look at an example of if statement.  
+
| Now let us look at an example of '''if ''' statement.  
 
   
 
   
 
|-
 
|-
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|-
 
|-
 
|01.43
 
|01.43
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|gedit conditionalBlocks dot pl space ampersand  
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|'''gedit conditionalBlocks dot pl ''' space '''&'''(ampersand )
 
   
 
   
 
|-
 
|-
 
|01.49
 
|01.49
−
|and press Enter
+
|and press '''Enter'''
 
   
 
   
 
|-
 
|-
 
|01.52
 
|01.52
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|This will open the conditionalBlocks.pl file in gedit.  
+
|This will open the '''conditionalBlocks.pl''' file in gedit.  
 
   
 
   
 
|-
 
|-
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|-
 
|-
 
|02.09
 
|02.09
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| Note the equal to equal to sign here. This is the comparison operator.  
+
| Note the equal to equal to sign here. This is the '''comparison''' operator.  
  
 
|-
 
|-
 
|02.15
 
|02.15
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|The condition $count equal to equal to 5 is checked against the value of variable count.  
+
|The condition '''$count equal to equal to 5 ''' is checked against the value of variable count.  
  
 
   
 
   
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|-
 
|-
 
| 02.28
 
| 02.28
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|Now, press ctrl+s to save the file.  
+
|Now, press '''ctrl+s''' to '''save''' the file.  
  
 
|-
 
|-
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|-
 
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|02.46
 
|02.46
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|perl hyphen c conditionalBlocks dot pl
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|'''perl hyphen c conditionalBlocks dot pl'''
  
 
|-
 
|-
 
| 02.53
 
| 02.53
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|  and press Enter.  
+
|  and press '''Enter. '''
 
   
 
   
 
|-
 
|-
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|  02.59
 
|  02.59
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| conditionalBlocks.pl syntax OK  
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| '''conditionalBlocks.pl syntax OK '''
  
 
   
 
   
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|-
 
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|03.10
 
|03.10
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|perl conditionalBlocks dot pl  
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|'''perl conditionalBlocks dot pl '''
 
   
 
   
 
|-
 
|-
 
| 03.14
 
| 03.14
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| and press Enter
+
| and press '''Enter'''
 
   
 
   
 
   
 
   
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|-
 
|-
 
| 03.19
 
| 03.19
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| I am inside if statement
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| ''' I am inside if statement'''
 
   
 
   
 
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|-
 
|03.26
 
|03.26
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|Alternately, we can write the above if statement as-  
+
|Alternately, we can write the above ''' if''' statement as-  
 
   
 
   
 
|-
 
|-
 
|03.31
 
|03.31
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|print space double quote I am inside if statement slash n double quote complete space if open bracket dollar count equal to equal to 5 close bracket semicolon.
+
|'''print ''' space double quote '''I am inside if statement''' slash '''n''' double quote complete space '''if''' open bracket '''dollar count equal to equal to 5''' close bracket semicolon.
  
 
|-
 
|-
 
|  03.57
 
|  03.57
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|Now, let us look at if-else statement.  
+
|Now, let us look at '''if-else''' statement.  
 
   
 
   
 
|-
 
|-
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|  04.13
 
|  04.13
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| The syntax for if-else condition is as follows -  
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| The syntax for '''if-else''' condition is as follows -  
  
 
|-
 
|-
 
|  04.17
 
|  04.17
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| if space open bracket condition close bracket space open curly bracket Press Enter.  
+
| '''if ''' space open bracket '''condition''' close bracket space open curly bracket Press Enter.  
 
   
 
   
 
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|-
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|04.32
 
|04.32
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|Press Enter  
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|Press '''Enter '''
  
 
|-
 
|-
 
|04.34
 
|04.34
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|close curly bracket space else space open curly bracket Enter
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|close curly bracket space '''else''' space open curly bracket '''Enter'''
 
   
 
   
 
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|-
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|-
 
|-
 
|04.47
 
|04.47
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|Press Enter close curly bracket  
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|Press '''Enter''' close curly bracket  
  
 
|-
 
|-
 
|04.51
 
|04.51
−
| Now again, go to the conditionalBlocks.pl file which we have already created in gedit.  
+
| Now again, go to the '''conditionalBlocks.pl''' file which we have already created in gedit.  
 
   
 
   
 
|-
 
|-
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| 05.07
 
| 05.07
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|   else  
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| ''' else '''
 
   
 
   
 
|-
 
|-
 
|05.09
 
|05.09
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| space open curly bracket press Enter  
+
| space open curly bracket press '''Enter '''
  
 
|-
 
|-
 
|05.14
 
|05.14
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|print space double quote I am inside else statement slash n  double quotes complete semicolon  
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|'''print''' space double quote '''I am inside else statement slash n''' double quotes complete semicolon  
 
   
 
   
 
|-
 
|-
 
|05.30
 
|05.30
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|Press Enter and close the curly bracket.  
+
|Press '''Enter''' and close the '''curly bracket.'''
  
 
|-
 
|-
 
|05.34
 
|05.34
−
|Here, 4 is assigned to variable $count.   
+
|Here, '''4''' is assigned to variable $count.   
 
   
 
   
 
|-
 
|-
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|-
 
|05.43
 
|05.43
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|the code within the if block will not get execute
+
|the code within the '''if''' block will not get execute
 
   
 
   
 
|-
 
|-
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|-
 
|-
 
|05.59
 
|05.59
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|and type perl hyphen c conditionalBlocks dot pl to check for any compilation or syntax error
+
|and type '''perl hyphen c conditionalBlocks dot pl''' to check for any compilation or syntax error
  
 
   
 
   
 
|-
 
|-
 
|  06.11
 
|  06.11
−
|  and press Enter
+
|  and press '''Enter'''
  
 
|-
 
|-
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| 06.17
 
| 06.17
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|  conditionalBlocks.pl syntax OK  
+
|  '''conditionalBlocks.pl''' syntax OK  
  
 
|-
 
|-
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|06.27
 
|06.27
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|Type perl conditionalBlocks dot pl  
+
|Type '''perl conditionalBlocks dot pl '''
  
  
 
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|-
 
|  06.33
 
|  06.33
−
| and press Enter
+
| and press '''Enter'''
  
 
|-
 
|-
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|06.39
 
|06.39
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|I am inside else statement
+
|'''I am inside else statement'''
 
   
 
   
 
|-
 
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|-
 
|-
 
|06.49
 
|06.49
−
|if and  
+
|'''if''' and  
 
   
 
   
 
|-
 
|-
 
|06.50
 
|06.50
−
|if-else conditional statements in Perl  
+
|'''if-else''' conditional statements in Perl  
 
   
 
   
 
|-
 
|-
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|-
 
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|  06.57
 
|  06.57
−
|  Print “It is an open source language”  
+
|  Print ''' “It is an open source language” '''
  
 
|-
 
|-
 
|07.01
 
|07.01
−
| when the variable declared has value 'Perl'  
+
| when the variable declared has value ''' 'Perl' '''
  
 
|-
 
|-
 
|07.04
 
|07.04
−
|otherwise print “It's a proprietary language”  
+
|otherwise print ''' “It's a proprietary language” '''
 
   
 
   
 
|-
 
|-

Revision as of 11:50, 8 May 2014

Visual Cue
Narration
00.01 Welcome to the spoken tutorial on if and if-else conditional statements in Perl.
00.07 In this tutorial, we will learn about;
00.09 if statement and
00.11 if-else statement in Perl
00.12 I am using Ubuntu Linux12.04 operating system and Perl 5.14.2


00.20 I will also be using the gedit Text Editor.


00.24 You can use any text editor of your choice.
00.28 You should have basic knowledge of Variables and Comments in Perl.


00.33 Knowledge of for, foreach , while and do-while loops in Perl will be an added advantage.
00.40 Please go through the relevant spoken tutorials on the spoken tutorial website.
00.45 Perl provides the following conditional statements -
00.49 if
00.50 if-else
00.51 if-elsif-else and
00.53 switch


00.54 In this tutorial, we'll cover if and If-else statements
00.59 if statement in Perl can be used
01.01 to execute a piece of code only when a specified condition is satisfied.
01.07 The syntax of if conditional statement is as follows


01.11 if space open bracket condition close bracket space Open curly bracket


01.19 Enter
01.20 Piece of code semicolon, to be executed when the condition is true


01.25 Enter, Close curly bracket


01.29 The code inside the if statement will be executed only when the condition is true.
01.36 Now let us look at an example of if statement.
01.40 Open the Terminal and type
01.43 gedit conditionalBlocks dot pl space &(ampersand )
01.49 and press Enter
01.52 This will open the conditionalBlocks.pl file in gedit.
01.57 Type the following piece of code as displayed on the screen.
02.02 Here we have specified a condition for if which checks the value of variable count.


02.09 Note the equal to equal to sign here. This is the comparison operator.
02.15 The condition $count equal to equal to 5 is checked against the value of variable count.


02.23 When it is equal to 5, the code within the if block will get executed.
02.28 Now, press ctrl+s to save the file.
02.32 Then switch to the terminal.
02.36 Make sure that you are in the directory in which you have saved your file.
02.41 Type the following to check for any compilation or syntax error -
02.46 perl hyphen c conditionalBlocks dot pl
02.53 and press Enter.
02.55 The following line will be displayed on the terminal window
02.59 conditionalBlocks.pl syntax OK


03.04 As there is no compilation or syntax error, we will execute the Perl script by typing -


03.10 perl conditionalBlocks dot pl
03.14 and press Enter


03.16 The following output will be shown on terminal.
03.19 I am inside if statement
03.23 Switch back to gedit
03.26 Alternately, we can write the above if statement as-
03.31 print space double quote I am inside if statement slash n double quote complete space if open bracket dollar count equal to equal to 5 close bracket semicolon.
03.57 Now, let us look at if-else statement.
04.01 This statement is used when user wants to execute


04.06 one piece of code when the condition is true and
04.09 another piece of code when the condition is false
04.13 The syntax for if-else condition is as follows -
04.17 if space open bracket condition close bracket space open curly bracket Press Enter.
04.27 piece of code semicolon
04.29 to be executed when if condition is true,


04.32 Press Enter
04.34 close curly bracket space else space open curly bracket Enter
04.41 another piece of code semicolon


04.43 to be executed when if condition is false
04.47 Press Enter close curly bracket
04.51 Now again, go to the conditionalBlocks.pl file which we have already created in gedit.
04.58 Assign 4 to count variable then at the end of the if block type space
05.07 else
05.09 space open curly bracket press Enter
05.14 print space double quote I am inside else statement slash n double quotes complete semicolon
05.30 Press Enter and close the curly bracket.
05.34 Here, 4 is assigned to variable $count.
05.38 As the value of count variable does not match 5,
05.43 the code within the if block will not get execute
05.47 instead the code within the else block will get execute.
05.52 Now press Ctrl+S to save the file.
05.56 Now switch to terminal.
05.59 and type perl hyphen c conditionalBlocks dot pl to check for any compilation or syntax error


06.11 and press Enter
06.13 The following line will be displayed on the terminal
06.17 conditionalBlocks.pl syntax OK
06.20 As there is no compilation or syntax error, we will now execute the Perl script.
06.27 Type perl conditionalBlocks dot pl


06.33 and press Enter
06.35 The following output will be shown on terminal.
06.39 I am inside else statement
06.44 Let us summarize.
06.46 In this tutorial, we have learnt -
06.49 if and
06.50 if-else conditional statements in Perl
06.53 using sample programs.
06.55 Here is assignment for you -
06.57 Print “It is an open source language”
07.01 when the variable declared has value 'Perl'
07.04 otherwise print “It's a proprietary language”
07.08 Watch the video available at the following link
07.11 It summaries the Spoken Tutorial project


07.15 If you do not have good bandwidth, you can download and watch it
07.20 The Spoken Tutorial Project Team
07.22 Conducts workshops using spoken tutorials


07.26 Gives certificates to those who pass an online test


07.31 For more details, please write to contact at spoken hyphen tutorial dot org
07.37 Spoken Tutorial Project is a part of the Talk to a Teacher project


07.42 It is supported by the National Mission on Education through ICT, MHRD, Government of India.


07.50 More information on this Mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro
08.00 Hope you enjoyed this Perl tutorial.
08.04 This is Amol Brahmankar signing off.


08.06 Thanks for joining.

Contributors and Content Editors

Gaurav, PoojaMoolya, Sandhya.np14

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