Difference between revisions of "Ruby/C2/Logical-and-other-Operators/English-timed"

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|-
 
|-
 
|  00:02
 
|  00:02
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| Welcome to this spoken tutorial on '''Logical & Other Operators. '''
+
| Welcome to this '''Spoken Tutorial''' on '''Logical & Other Operators. '''
  
 
|-
 
|-
 
| 00:06
 
| 00:06
−
| In this tutorial we will learn  
+
| In this tutorial, we will learn:
  
 
|-
 
|-
 
| 00:09
 
| 00:09
−
| '''Logical Operators '''
+
|* '''Logical Operators '''
  
 
|-
 
|-
 
| 00:11
 
| 00:11
−
|'''Parallel assignment''' and  
+
|*'''Parallel assignment''' and  
  
 
|-
 
|-
 
| 00:13
 
| 00:13
−
| '''Range Operators '''
+
|* '''Range Operators '''.
  
 
|-
 
|-
 
|  00:15
 
|  00:15
−
|Here we are using  
+
|Here we are using:
  
 
|-
 
|-
 
|  00:17
 
|  00:17
−
| '''Ubuntu Linux''' version 12.04  
+
|* '''Ubuntu Linux''' version '''12.04'''
  
 
|-
 
|-
 
|  00:20
 
|  00:20
−
| ''' Ruby 1.9.3  '''
+
|* ''' Ruby 1.9.3  '''
  
 
|-
 
|-
 
| 00:23
 
| 00:23
−
|To follow this tutorial you must know how to use ''' Terminal''' and '''Text editor''' in ''' Linux'''.  
+
|To follow this tutorial, you must know how to use ''' Terminal''' and '''Text editor''' in '''Linux'''.  
  
 
|-
 
|-
 
| 00:29
 
| 00:29
−
|You must also be familiar with '''irb'''  
+
|You must also be familiar with '''irb'''.
 
    
 
    
 
|-
 
|-
 
|  00:33
 
|  00:33
−
| If not, for relevant tutorials, please visit our website  
+
| If not, for relevant tutorials, please visit our website.
  
 
|-
 
|-
 
| 00:38
 
| 00:38
−
|Logical Operators are also known as ''' Boolean Operators'''
+
|'''Logical operators''' are also known as ''' Boolean operators'''
  
 
|-
 
|-
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|-
 
|-
 
| 00:48
 
| 00:48
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|'''Logical Operators''' are,
+
|'''Logical Operators''' are-
  
 
|-
 
|-
 
| 00:51
 
| 00:51
−
| ''' double ampersand (&&)'''  that is '''(and)'''  
+
|*  double ampersand (&&) that is '''(and)'''  
  
 
|-
 
|-
 
| 00:54
 
| 00:54
−
| ''' double pipe '''  that is '''(or)'''  
+
|*  double '''pipe'''  that is '''(or)'''  
  
 
|-
 
|-
 
| 00:56
 
| 00:56
−
|''' Exclamation (!)'''  that is '''(not)'''  
+
|*  Exclamation (!) that is '''(not)'''  
  
 
|-
 
|-
 
|  01:00
 
|  01:00
−
|  '''&&(double ampersand)''' and '''and''' evaluate to '''true''' only if both the expressions are '''true.'''  
+
|* '&&' (double ampersand) and '''and''' evaluate to '''true''' only if both the expressions are '''true.'''  
  
 
|-
 
|-
 
| 01:07
 
| 01:07
−
|Second expression is evaluated only if the first is '''true. '''  
+
|Second expression is evaluated only if the first is '''true.'''  
  
 
|-
 
|-
 
| 01:12
 
| 01:12
−
| Difference in the two forms is, precedence
+
| Difference in the two forms is precedence.
  
 
|-
 
|-
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|-
 
|-
 
| 01:20
 
| 01:20
−
|Let's us see some examples now.  
+
|Let's see some examples now.  
  
 
|-
 
|-
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|-
 
|-
 
|  01:25
 
|  01:25
−
|  Open the ''' terminal''' by pressing '''Ctrl, Alt and T''' keys simultaneously.  
+
|  Open the ''' terminal''' by pressing '''Ctrl, Alt''' and '''T''' keys simultaneously.  
  
 
|-
 
|-
 
|  01:31
 
|  01:31
−
|Type '''irb''' and press '''Enter''' to launch '''interactive Ruby'''
+
|Type "irb" and press '''Enter''' to launch '''interactive Ruby'''.
  
 
|-
 
|-
 
|  01:36
 
|  01:36
−
| Type ''' 3 greater than 2 space double ampersand space 4 less than 5'''  
+
| Type: ''' 3 greater than 2 space double ampersand space 4 less than 5'''.
  
 
|-
 
|-
 
| 01:47
 
| 01:47
−
| Press ''' Enter'''
+
| Press ''' Enter'''.
  
 
|-
 
|-
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|-
 
|-
 
| 01:53
 
| 01:53
−
|Here, '''expression1'''  that is 3>2 is '''true'''.  
+
|Here, expression1 that is 3>2 is '''true'''.  
  
 
|-
 
|-
 
| 01:59
 
| 01:59
−
|'''Expression 2''' that is 4<5 is also '''true.'''  
+
|Expression 2 that is 4<5 is also '''true.'''  
  
 
|-
 
|-
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|-
 
|-
 
| 02:08
 
| 02:08
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|Now press '''Up Arrow''' key to get the previous command.  
+
|Now, press '''Up-Arrow''' key to get the previous command.  
  
 
|-
 
|-
 
|02:12
 
|02:12
−
| And ''' replace the double ampersand''' symbol with the word ''' and.'''
+
| And replace the double ampersand symbol with the word "and".  
  
 
|-
 
|-
 
| 02:17
 
| 02:17
−
|  Press '''Enter '''
+
|  Press '''Enter'''.
  
 
|-
 
|-
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|-
 
|-
 
|  02:22
 
|  02:22
−
| Now press up arrow key again to get the previous command.  
+
| Now, press up-arrow key again to get the previous command.  
  
 
|-
 
|-
 
|  02:27
 
|  02:27
−
| In ''' expression 1''' replace '''greater than''' sign with '''less than'''
+
| In expression1, replace greater-than sign with less-than,
  
 
|-
 
|-
 
| 02:32
 
| 02:32
−
|Press ''' Enter '''
+
|press ''' Enter '''
  
 
|-
 
|-
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|-
 
|-
 
| 02:38
 
| 02:38
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|This is because ''' 3<2''' is '''false.'''
+
|This is because 3 < 2 is '''false.'''
  
 
|-
 
|-
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|-
 
|-
 
| 03:15
 
| 03:15
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|''' 10 greater than 6 space double pipe space 12 less than 7'''
+
|Type: '''10 greater than 6 space double pipe space 12 less than 7'''
  
 
|-
 
|-
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|-
 
|-
 
| 03:29
 
| 03:29
−
|Here '''expression 1''' that is '''10>6''' is '''true'''.
+
|Here '''expression 1''', that is '''10>6''' is '''true'''.
  
 
|-
 
|-
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|-
 
|-
 
|  03:42
 
|  03:42
−
|  Now press the '''Up Arrow''' key to get the previous command.  
+
|  Now press the '''Up-Arrow''' key to get the previous command.  
  
 
|-
 
|-
 
|  03:46
 
|  03:46
−
|  In '''expression 1''' replace '''greater than sign''' with '''less than sign.'''
+
|  In '''expression 1''' replace '''greater than''' sign with '''less than''' sign
  
 
|-
 
|-
 
|  03:52
 
|  03:52
−
|  And replace '''pipe''' symbol with the word '''or.'''  
+
|  and replace '''pipe''' symbol with the word '''or.'''  
  
 
|-
 
|-
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|-
 
|-
 
| 07:20
 
| 07:20
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|Now let's swap a and b.
+
|Now let's swap 'a' and 'b'.
  
 
|-
 
|-
 
| 07:23
 
| 07:23
−
|To do so type  
+
|To do so, type:
  
 
|-
 
|-
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|-
 
|-
 
| 07:33
 
| 07:33
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| Press '''Up Arrow''' key twice to get the '''puts''' command and press '''Enter.'''
+
| Press '''Up-Arrow''' key twice to get the '''puts''' command and press '''Enter.'''
  
 
|-
 
|-
 
|  07:39
 
|  07:39
−
|  We get the output as  
+
|  We get the output as-
  
 
|-
 
|-
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|-
 
|-
 
| 07:44
 
| 07:44
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| '''b=10 '''
+
| '''b=10 '''.
  
 
|-
 
|-
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|-
 
|-
 
| 07:50
 
| 07:50
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|The values in a '''range''' can be numbers, characters, strings or objects.  
+
|The values in a '''range''' can be numbers, characters, '''string'''s or '''object'''s.  
  
 
|-
 
|-
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|-
 
|-
 
| 08:36
 
| 08:36
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|Type '''Within brackets 1 two dots 10 then dot to underscore a '''
+
|Type: within brackets ''' 1 two dots 10''' then '''dot to underscore a'''  
  
 
|-
 
|-
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|-
 
|-
 
| 09:16
 
| 09:16
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|Type  '''Within brackets 1 three dots 10 then dot to underscore a '''
+
|Type: within brackets '''1 three dots 10''' then '''dot to underscore a'''.
  
 
|-
 
|-
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|-
 
|-
 
| 09:39
 
| 09:39
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|Here the end value 10 is not included in the range.  
+
|Here, the end value 10 is not included in the range.  
  
 
|-
 
|-
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|-
 
|-
 
| 09:50
 
| 09:50
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|Type '''Within brackets 1 two dots 10 three times equal to and then 5 '''
+
|Type: within brackets '''1 two dots 10 three times equal to''' and then '''5'''.
  
 
|-
 
|-
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|-
 
|-
 
| 10:17
 
| 10:17
−
|In this tutorial, we have learnt  
+
|In this tutorial, we have learnt:
  
 
|-
 
|-
 
| 10:20
 
| 10:20
−
|'''Logical operator''' i.e ''' double ampersand, double pipe and exclamation mark operators '''
+
|'''Logical operator''' i.e double ampersand, double '''pipe''' and exclamation mark operators.
  
 
|-
 
|-
 
| 10:27
 
| 10:27
−
|'''Parallel assignment''' Ex: a,b,c=10,20,30  
+
|'''Parallel assignment''' Ex: a, b, c = 10, 20, 30  
  
 
|-
 
|-
 
| 10:34
 
| 10:34
−
|'''Range Operator Inclusive operator '''(..) and Exclusive operator(...)'''
+
|'''Range Operator Inclusive operator '''(..) and Exclusive operator(...)'''.
  
 
|-
 
|-
 
| 10:39
 
| 10:39
−
|As an assignment  
+
|As an assignment,
  
 
|-
 
|-
 
| 10:41
 
| 10:41
−
|Declare two variables using '''parallel assignment''' and  
+
|declare two variables using '''parallel assignment''' and  
  
 
|-
 
|-
 
| 10:45
 
| 10:45
−
|Check whether their sum lies between 20 and 50  
+
|check whether their sum lies between 20 and 50.
  
 
|-
 
|-
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|-
 
|-
 
| 10:52
 
| 10:52
−
|It summarises the Spoken Tutorial project.
+
|It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
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|-
 
|-
 
|  11:00
 
|  11:00
−
| The Spoken Tutorial Project Team :
+
| The Spoken Tutorial project team:
  
 
|-   
 
|-   
 
| 11:03
 
| 11:03
−
|Conducts workshops using spoken tutorials  
+
|* Conducts workshops using spoken tutorials.
  
 
|-
 
|-
 
|11:05
 
|11:05
−
|Gives certificates to those who pass an online test  
+
|* Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
| 11:09
 
| 11:09
−
|For more details, please write to contact@spoken-tutorial.org
+
|For more details, please write to:
 +
contact@spoken-tutorial.org
  
 
|-
 
|-
 
|  11:15
 
|  11:15
−
| 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.
  
 
|-
 
|-
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|-
 
|-
 
| 11:25
 
| 11:25
−
|More information on this Mission is available at 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.
  
 
|-
 
|-
 
| 11:34
 
| 11:34
−
|This script has been contributed by the spoken tutorial team IIT Bombay  
+
|This script has been contributed by the spoken tutorial team, '''IIT Bombay'''.
  
 
|-
 
|-
 
| 11:38
 
| 11:38
−
|And this is Shalini Nair signing off  Thank you  
+
|And this is Shalini Nair, signing off. Thank you.
  
 
|}
 
|}

Revision as of 10:51, 29 October 2015

Time Narration
00:02 Welcome to this Spoken Tutorial on Logical & Other Operators.
00:06 In this tutorial, we will learn:
00:09 * Logical Operators
00:11 *Parallel assignment and
00:13 * Range Operators .
00:15 Here we are using:
00:17 * Ubuntu Linux version 12.04
00:20 * Ruby 1.9.3
00:23 To follow this tutorial, you must know how to use Terminal and Text editor in Linux.
00:29 You must also be familiar with irb.
00:33 If not, for relevant tutorials, please visit our website.
00:38 Logical operators are also known as Boolean operators
00:42 because they evaluate parts of an expression
00:45 and return a true or false value.
00:48 Logical Operators are-
00:51 * double ampersand (&&) that is (and)
00:54 * double pipe that is (or)
00:56 * Exclamation (!) that is (not)
01:00 * '&&' (double ampersand) and and evaluate to true only if both the expressions are true.
01:07 Second expression is evaluated only if the first is true.
01:12 Difference in the two forms is precedence.
01:15 Symbolic and that is&&(double ampersand) has higher precedence.
01:20 Let's see some examples now.
01:22 We will use irb for this.
01:25 Open the terminal by pressing Ctrl, Alt and T keys simultaneously.
01:31 Type "irb" and press Enter to launch interactive Ruby.
01:36 Type: 3 greater than 2 space double ampersand space 4 less than 5.
01:47 Press Enter.
01:49 We get the output as true.
01:53 Here, expression1 that is 3>2 is true.
01:59 Expression 2 that is 4<5 is also true.
02:03 Since both the expressions are true, we get output as true.
02:08 Now, press Up-Arrow key to get the previous command.
02:12 And replace the double ampersand symbol with the word "and".
02:17 Press Enter.
02:19 We get the same result.
02:22 Now, press up-arrow key again to get the previous command.
02:27 In expression1, replace greater-than sign with less-than,
02:32 press Enter
02:35 We get the output as false.
02:38 This is because 3 < 2 is false.
02:43 Since the first expression is false, the second expression will not be evaluated.
02:49 So, we get output as false.
02:53 double pipe and or evaluate to true, if either expression is true.
02:59 Second expression is evaluated only if first is false.
03:04 Difference in the two forms is precedence.
03:07 Symbolic or i.e double pipe has higher precedence.
03:11 Now, let's try some examples.
03:15 Type: 10 greater than 6 space double pipe space 12 less than 7
03:23 Press Enter.
03:26 We get output as true.
03:29 Here expression 1, that is 10>6 is true.
03:35 Since the first expression is true , second expression will not be evaluated.
03:40 So, we get the output as true.
03:42 Now press the Up-Arrow key to get the previous command.
03:46 In expression 1 replace greater than sign with less than sign
03:52 and replace pipe symbol with the word or.
03:57 Press Enter.
04:00 Here, expression1 that is 10<6 is false.
04:05 Expression 2 that is 12<7 is also false.
04:10 Since both the expressions are false, we get output as false.
04:15 ! (exclamation mark ) and not operators return the opposite value of the expression
04:20 If the expression is true, exclamation mark operator will return a false value.
04:27 It will return true if the expression is false.
04:30 Difference in the two forms is precedence.
04:33 Symbolic not that is (!) has higher precedence.
04:37 Let's try out the not operator.
04:40 First type 10 double equal to 10
04:45 Press Enter
04:47 We get the output as true.
04:50 To invert the result of above expression,
04:53 let's add the not operator before the expression.
04:57 Type Exclamation mark within brackets 10 double equal to 10
05:04 Press Enter.
05:06 We get the output as false.
05:10 Press Ctrl+L simultaneously to clear the irb console.
05:15 Next, let us learn about parallel assignment.
05:20 Multiple variables can be initialized with a single line of Ruby code, through parallel assignment.
05:26 Let's switch to the terminal.
05:29 Let's declare three variables a, b, c using parallel assignment.
05:36 Type a comma b comma c equal to 10 comma 20 comma 30
05:45 and press Enter.
05:47 Here, 10 will be assigned to variable a
05:52 20 will be assigned to variable b
05:54 30 will be assigned to variable c
05:56 The right hand side acts as an array.
06:01 If we list multiple variables on the left hand side, then the array is unpacked and assigned into the respective variables.
06:10 We will learn about arrays in detail in the upcoming tutorials.
06:14 For now, let's check whether the assignment is done properly.
06:20 Type a and press Enter.
06:23 Value 10 stored in variable a is displayed.
06:28 Type b and press Enter.
06:31 We get 20
06:33 Type c and press Enter.
06:37 30 is displayed.
06:40 Parallel assignment is also useful for swapping the values stored in two variables.
06:45 Let us swap the values of variables a and b.
06:50 Type puts space within double quotes a equal to hash within curly brackets a comma within double quotes b equal to hash within curly brackets b
07:11 Press Enter.
07:13 We get the output as a=10
07:16 b=20
07:20 Now let's swap 'a' and 'b'.
07:23 To do so, type:
07:25 a comma b equal to b comma a
07:31 Press Enter.
07:33 Press Up-Arrow key twice to get the puts command and press Enter.
07:39 We get the output as-
07:41 a=20
07:44 b=10 .
07:47 We will now learn about range in Ruby.
07:50 The values in a range can be numbers, characters, strings or objects.
07:58 Ranges are used to express a sequence.
08:02 Sequence range is used to create a range of successive values.
08:06 It consists of a start value, range of values and an end value.
08:13 (..) two dot operator creates inclusive range.
08:16 (...) three dot operator creates an exclusive range.
08:20 Ranges are used to identify whether a value falls within a particular range, too.
08:26 We do this using (===) the equality operator.
08:30 Let us try out some examples on ranges.
08:33 Let's switch to terminal.
08:36 Type: within brackets 1 two dots 10 then dot to underscore a
08:46 Two dot operator creates inclusive range.
08:50 Inclusive operator includes both begin and end values in a range.
08:57 Here to_a method is used to convert a range to a list.
09:03 Press Enter.
09:05 Here you can see the values 1 and 10 are included in the range.
09:11 Now we will see an exclusive range operator.
09:16 Type: within brackets 1 three dots 10 then dot to underscore a.
09:27 Three dot operator creates an exclusive range.
09:31 Exclusive range operator excludes the end value from the sequence.
09:37 Press Enter.
09:39 Here, the end value 10 is not included in the range.
09:45 Now let's check whether 5 lies in the range of 1 to 10.
09:50 Type: within brackets 1 two dots 10 three times equal to and then 5.
10:00 Press Enter.
10:02 Equality operator is used to check whether a value lies in the range.
10:07 We get the output as true since 5 lies in the range 1 to 10.
10:14 This brings us to the end of this Spoken Tutorial.
10:17 In this tutorial, we have learnt:
10:20 Logical operator i.e double ampersand, double pipe and exclamation mark operators.
10:27 Parallel assignment Ex: a, b, c = 10, 20, 30
10:34 Range Operator Inclusive operator (..) and Exclusive operator(...).
10:39 As an assignment,
10:41 declare two variables using parallel assignment and
10:45 check whether their sum lies between 20 and 50.
10:49 Watch the video available at the following link.
10:52 It summarizes the Spoken Tutorial project.
10:56 If you do not have good bandwidth, you can download and watch it.
11:00 The Spoken Tutorial project team:
11:03 * Conducts workshops using spoken tutorials.
11:05 * Gives certificates to those who pass an online test.
11:09 For more details, please write to:

contact@spoken-tutorial.org

11:15 Spoken Tutorial project is a part of the Talk to a Teacher project.
11:19 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
11:25 More information on this mission is available at:

spoken hyphen tutorial dot org slash NMEICT hyphen Intro.

11:34 This script has been contributed by the spoken tutorial team, IIT Bombay.
11:38 And this is Shalini Nair, signing off. Thank you.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Ranjana, Sandhya.np14

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