Difference between revisions of "PERL/C2/for-for-each-loops/English-timed"

From Script | Spoken-Tutorial
Jump to: navigation, search
Line 5: Line 5:
 
|-
 
|-
 
| 00:01
 
| 00:01
−
|Welcome to the spoken tutorial on '''for '''and''' foreach Loops''' in '''Perl'''
+
|Welcome to the spoken tutorial on '''for '''and''' foreach Loops''' in '''Perl'''.
 
   
 
   
 
|-
 
|-
Line 12: Line 12:
 
|-
 
|-
 
|00:11
 
|00:11
−
|'''foreach''' loop in '''Perl'''
+
|'''foreach''' loop in '''Perl'''.
 
   
 
   
 
|-
 
|-
 
|00:13
 
|00:13
−
| I am using '''Ubuntu Linux12.04''' operating system and '''Perl 5.14.2'''
+
| I am using '''Ubuntu Linux 12.04''' operating system and '''Perl 5.14.2'''.
 
   
 
   
 
|-
 
|-
Line 28: Line 28:
 
|-
 
|-
 
| 00:29
 
| 00:29
−
| You should have basic knowledge of '''Variables '''and''' Comments '''in''' Perl.'''
+
| You should have basic knowledge of variables and comments in''' Perl.'''
 
   
 
   
 
|-
 
|-
Line 40: Line 40:
 
|-
 
|-
 
| 00:49
 
| 00:49
−
|  There are various types of loops in Perl;
+
|  There are various types of loops in Perl:
 
   
 
   
 
|-
 
|-
 
|00:52
 
|00:52
−
|'''for loop'''
+
|* '''for loop'''
 
   
 
   
 
|-
 
|-
 
|00:53
 
|00:53
−
|'''foreach loop'''
+
|* '''foreach loop'''
 
   
 
   
 
|-
 
|-
 
|00:54
 
|00:54
−
|'''while loop &'''
+
|* '''while loop''' and
 
   
 
   
 
|-
 
|-
 
|00:55
 
|00:55
−
|'''do-while loop'''
+
|* '''do-while loop'''.
  
 
|-
 
|-
 
|00:56
 
|00:56
−
|In this tutorial, we'll cover '''for''' and '''foreach loop'''.
+
|In this tutorial, we will cover '''for''' and '''foreach loop'''.
 
   
 
   
 
|-
 
|-
 
|01:01
 
|01:01
−
| '''for '''loop in '''Perl''' can be used to execute a piece of code for a certain number of times.
+
| '''for''' loop in '''Perl''' can be used to execute a piece of code for a certain number of times.
 
   
 
   
 
|-
 
|-
Line 74: Line 74:
 
|-
 
|-
 
|01:20
 
|01:20
−
|close bracket''' Press '''Enter'''
+
|close bracket''', press '''Enter'''.
  
 
|-
 
|-
 
|01:22
 
|01:22
−
|Open curly brackets
+
|Open curly brackets,
 
   
 
   
 
|-
 
|-
 
|01:24
 
|01:24
−
|Piece of code to be executed multiple times
+
|piece of code to be executed multiple times,
  
 
|-
 
|-
 
|01:28
 
|01:28
−
|Close curly brackets
+
|close curly brackets.
 
   
 
   
 
|-
 
|-
Line 94: Line 94:
 
|-
 
|-
 
| 01:33
 
| 01:33
−
| Open the '''Terminal''' and type; '''gedit forLoop.pl space & (ampersand)'''
+
| Open the '''Terminal''' and type: '''gedit forLoop.pl space & (ampersand)'''
 
   
 
   
 
|-
 
|-
 
|01:42
 
|01:42
−
|and press''' Enter'''
+
|and press''' Enter'''.
 
   
 
   
 
|-
 
|-
Line 106: Line 106:
 
|-
 
|-
 
| 1:48
 
| 1:48
−
| Type the following piece of code;'''hash exclamation mark slash u s r slash bin slash perl'''
+
| Type the following piece of code: '''hash exclamation mark slash u s r slash bin slash perl'''
 
   
 
   
 
|-
 
|-
 
|01:58
 
|01:58
−
|Press '''Enter'''
+
|press '''Enter'''.
 
   
 
   
 
|-
 
|-
Line 122: Line 122:
 
|-
 
|-
 
|02:19
 
|02:19
−
|Open curly bracket  press enter
+
|Open curly bracket  press '''Enter'''.
 
   
 
   
 
|-
 
|-
 
|02:21
 
|02:21
−
| type'''print space double quote Value of i colon space dollar i slash n''' close double quote '''semicolon '''
+
| Type: '''print space double quote Value of i colon <space> dollar i slash n''' double quote complete semicolon  
 
   
 
   
 
|-
 
|-
 
|02:35
 
|02:35
−
| And Press '''Enter'''  
+
| and press '''Enter'''.
 
   
 
   
 
|-
 
|-
 
|02:36
 
|02:36
−
|now close curly bracket
+
|Now close curly bracket.
 
   
 
   
 
|-
 
|-
Line 265: Line 265:
 
|-
 
|-
 
|05:12
 
|05:12
−
| Type the following piece of code
+
| Type the following piece of code:
 
|-
 
|-
 
|05:15
 
|05:15
−
|'''hash exclamation mark slash u s r slash bin slash perl''' and Press '''Enter'''
+
|'''hash exclamation mark slash u s r slash bin slash perl''' and press '''Enter'''.
 
   
 
   
 
|-
 
|-
Line 276: Line 276:
 
|-
 
|-
 
|05:39
 
|05:39
−
|press enter
+
|press '''Enter'''.
 
   
 
   
 
|-
 
|-
Line 339: Line 339:
 
|-
 
|-
 
|07:24
 
|07:24
−
|type '''perl hyphen c foreachLoop dot pl'''and press''' Enter.'''
+
|Type: '''perl hyphen c foreachLoop dot pl'''and press''' Enter.'''
 
   
 
   
 
|-
 
|-
 
| 07:32
 
| 07:32
−
|  The following line will be shown on terminal
+
|  The following line will be shown on terminal.
 
   
 
   
 
|-
 
|-
Line 351: Line 351:
 
|-
 
|-
 
|07:38
 
|07:38
−
|So let us execute the '''Perl''' script.
+
|So, let us execute the '''Perl''' script.
  
 
|-
 
|-
 
|07:41
 
|07:41
−
|Type  '''perl foreachLoop dot pl''' and press '''Enter'''
+
|Type: '''perl foreachLoop dot pl''' and press '''Enter'''.
 
   
 
   
 
|-
 
|-
 
| 07:48
 
| 07:48
−
|   The following output will be shown on terminal.
+
| The following output will be shown on terminal.
 
|-
 
|-
 
|  07:54
 
|  07:54
Line 366: Line 366:
 
|-
 
|-
 
|  07:57
 
|  07:57
−
| Let us summarize.
+
| Let us summarize.
 
   
 
   
 
|-
 
|-
Line 382: Line 382:
 
|-
 
|-
 
| 08:07
 
| 08:07
−
| Here is an assignment for you -
+
|Here is an assignment for you -
 
   
 
   
 
|-
 
|-
Line 389: Line 389:
 
|-
 
|-
 
|08:13
 
|08:13
−
| Print it 5 times
+
| print it 5 times.
 
|-
 
|-
 
|08:16
 
|08:16
Line 395: Line 395:
 
|-
 
|-
 
|08:32
 
|08:32
−
| Print the element of an array using '''foreach''' loop
+
| print the element of an array using '''foreach''' loop.
 
   
 
   
 
|-
 
|-
 
|08:36
 
|08:36
−
|Watch the video available at the following link
+
|Watch the video available at the following link.
 
   
 
   
 
|-
 
|-
 
|08:40
 
|08:40
−
|It summaries the Spoken Tutorial project
+
|It summaries the Spoken Tutorial project.
 
   
 
   
 
|-
 
|-
 
|08:43
 
|08:43
−
|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.
 
   
 
   
 
|-
 
|-
 
| 08:48
 
| 08:48
−
|  The Spoken Tutorial Project Team  Conducts workshops using spoken tutorials
+
|  The Spoken Tutorial Project Team: Conducts workshops using spoken tutorials.
 
   
 
   
 
|-
 
|-
 
|08:55
 
|08:55
−
|Gives certificates to those who pass an online test
+
|Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
|08:59
 
|08:59
−
|For more details, please write to contact at spoken hyphen tutorial dot org
+
|For more details, please write to contact at spoken hyphen tutorial dot org.
 
   
 
   
 
|-
 
|-
 
| 09:07
 
| 09:07
−
|  Spoken Tutorial Project is a part of the Talk to a Teacher project
+
|  "Spoken Tutorial" project is a part of the "Talk to a Teacher" project.
 
   
 
   
 
|-
 
|-
Line 431: Line 431:
 
|-
 
|-
 
|09:20
 
|09:20
−
|More information on this Mission is available spoken hyphen tutorial dot org slash NMEICT hyphen Intro
+
|More information on this mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro.
 
   
 
   
 
|-
 
|-
 
| 09:31
 
| 09:31
−
| Hope you enjoyed this Perl tutorial.  
+
|Hope you enjoyed this '''Perl''' tutorial.  
 
   
 
   
 
|-
 
|-
 
|09:34
 
|09:34
−
|This is Amol signing off.
+
|This is Amol, signing off.
  
 
|-
 
|-

Revision as of 17:38, 7 May 2015

Time Narration
00:01 Welcome to the spoken tutorial on for and foreach Loops in Perl.
00:06 In this tutorial, we will learn about: for loop in Perl and
00:11 foreach loop in Perl.
00:13 I am using Ubuntu Linux 12.04 operating system and Perl 5.14.2.
00:21 I will also be using the gedit Text Editor.
00:25 You can use any text editor of your choice.
00:29 You should have basic knowledge of variables and comments in Perl.
00:33 If not, please go through the relevant spoken tutorials on the spoken tutorial website.
00:40 Perl provides a mechanism by which we can check a condition repeatedly for various values. This is done using loops.
00:49 There are various types of loops in Perl:
00:52 * for loop
00:53 * foreach loop
00:54 * while loop and
00:55 * do-while loop.
00:56 In this tutorial, we will cover for and foreach loop.
01:01 for loop in Perl can be used to execute a piece of code for a certain number of times.
01:07 The syntax of for loop is as follows:
01:10 for space open bracket variable initialization semicolon condition semicolon increment
01:20 close bracket, press Enter.
01:22 Open curly brackets,
01:24 piece of code to be executed multiple times,
01:28 close curly brackets.
01:30 Now let us look at an example of a for loop.
01:33 Open the Terminal and type: gedit forLoop.pl space & (ampersand)
01:42 and press Enter.
01:43 This will open the forLoop.pl file in gedit.
1:48 Type the following piece of code: hash exclamation mark slash u s r slash bin slash perl
01:58 press Enter.
02:00 for space open bracket dollar i equals to zero semicolon space dollar i less than or equal to four semicolon space dollar i plus plus close bracket
02:18 space
02:19 Open curly bracket press Enter.
02:21 Type: print space double quote Value of i colon <space> dollar i slash n double quote complete semicolon
02:35 and press Enter.
02:36 Now close curly bracket.
02:39 Press Ctrl+S to save the file.
02:42 Let me explain what the for loop does.
02:46 The variable i is initialized to zero.
02:50 Next, the condition is checked.
02:53 In this case, the condition is i less than or equal to 4.
02:59 If this condition is true, the code within the curly bracket will be executed.
03:05 This means the first print statement "Value of i colon 0"
03:11 will be displayed on the terminal.
03:14 After this, the variable i is incremented by 1.
03:18 And the for loop condition is checked once again.
03:23 This loop will exit when the value of i becomes greater than 4.
03:29 In this case, the for loop will be executed for i = 0, 1, 2, 3, 4
03:38 which is a total of 5 times.
03:41 Now, switch to terminal.
03:44 Type the following to check for any compilation or syntax error:
03:48 perl hyphen c forLoop dot pl
03:54 and press Enter.
03:56 Here it displays a message
03:58 forLoop.pl syntax OK
04:01 So, we have no errors.
04:03 Now, let's execute the Perl script by typing perl forLoop dot pl and press Enter.
04:11 The following output will be shown on terminal.
04:16 Now, let us look at foreach loop.
04:19 If we want to iterate a condition for an array, we can make use of foreach loop.
04:25 The syntax is: foreach space dollar variable space within brackets at the rate array space
04:35 open curly bracket
04:37 perform action on each element of an array Press Enter
04:42 Close the curly bracket.
04:44 Please note: We'll cover array, array initialization and defining an array in subsequent tutorials.
04:52 Now let us look at an example of foreach loop.
04:56 Open the Terminal and type gedit foreachLoop dot pl space ampersandand Press Enter
05:08 This will open the foreachLoop.pl file in gedit.
05:12 Type the following piece of code:
05:15 hash exclamation mark slash u s r slash bin slash perl and press Enter.
05:25 at the rate myarray space is equal to space open bracket ten comma twenty comma thirty close bracket semicolon
05:39 press Enter.
05:41 foreach space dollar var space open bracket at the rate myarray close bracket space
05:52 Open curly bracket press enter and type
05:56 'print space double quote Element of an array is colon dollar var slash n close double quote semicolon
06:13 Press Enter and Close the curly bracket
06:17 Press ctrl+s to save the file.
06:20 Let me explain what this code does. An array myarray is declared.
06:27 It has 3 elements 10, 20 and 30.
06:33 In each iteration of foreach loop dollar var will contain the single element of an array
06:40 foreach keyword will repeat this loop for each element of an array.
06:47 That is, the code within the curly bracket will be executed for each myarray element.
06:55 Back-slash n will place the prompt on a new line.
07:00 This means the first element '10' will be displayed on the terminal.
07:06 Then 20 and so on, till all the elements are printed.
07:12 This loop will exit after printing all the elements in myarray.
07:17 Now, switch to terminal and type the following to check for any compilation or syntax error.
07:24 Type: perl hyphen c foreachLoop dot pland press Enter.
07:32 The following line will be shown on terminal.
07:36 There are no compilation or syntax errors.
07:38 So, let us execute the Perl script.
07:41 Type: perl foreachLoop dot pl and press Enter.
07:48 The following output will be shown on terminal.
07:54 So, that's it about for loop and foreach loop.
07:57 Let us summarize.
07:59 In this tutorial, we have learnt -
08:02 for loop and foreach loop in Perl
08:06 using some sample programs.
08:07 Here is an assignment for you -
08:10 Declare a string as 'Spoken Tutorial' and
08:13 print it 5 times.
08:16 Declare an array of colors as @colorArray = open bracket in single quote red comma white comma blue close the bracket and
08:32 print the element of an array using foreach loop.
08:36 Watch the video available at the following link.
08:40 It summaries the Spoken Tutorial project.
08:43 If you do not have good bandwidth, you can download and watch it.
08:48 The Spoken Tutorial Project Team: Conducts workshops using spoken tutorials.
08:55 Gives certificates to those who pass an online test.
08:59 For more details, please write to contact at spoken hyphen tutorial dot org.
09:07 "Spoken Tutorial" project is a part of the "Talk to a Teacher" project.
09:12 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
09:20 More information on this mission is available at spoken hyphen tutorial dot org slash NMEICT hyphen Intro.
09:31 Hope you enjoyed this Perl tutorial.
09:34 This is Amol, signing off.
09:36 Thanks for joining.

Contributors and Content Editors

Gaurav, Madhurig, PoojaMoolya, Sandhya.np14, Sneha

Retrieved from "https://script.spoken-tutorial.org/index.php?title=PERL/C2/for-for-each-loops/English-timed&oldid=21847"